1 In 6 Serial Killers Are Women, Here's Why - Dr Marissa Harrison

why is it particularly interesting to study female serial killers I think it's interesting because there seems to be this preconceived notions that all serial killers operate the same way and when we think of a serial killer we think of in the United States at least Ted Bundy or Ed keer we think about monstrous males who commit sex crimes and female serial killers might be monstrous per some people's definitions but they tend to be more lowkey they tend to poison people they tend to kill for money and power versus male serial killers tend to kill for sex so there are profound sex differences so I think it's interesting to bring that to public attention right so you're like a uh a promoter of females not not a promoter not quite saying that they're good but just maybe a little bit more attention should be paid why have they been so neglected beyond the fact that maybe the way that they kill is less extravagant I I agree with you first let me say when I was writing the book justi as deadly the psychology of female serial killers I was thinking to myself is this a feminist book because I'm saying women can do that too and it's a really horrible argument of equality but the thing is they can um so you had asked why might people pay attention to males more so than females and I think there's this age-old notion and I'm certainly not the first person to say this but I think there's this age-old notion that women can't be damaging women can't be dangerous women are nurturing and caregivers right so if I said to you Grandma you might think of well let me ask you this Chris what do you think of when you think of Grandma soft gentle caring mothering sleepy exactly sleep right exactly what if I told you about the giggling granny Nanny Doss who killed her mother her likely her sister her I think three husbands some of her grandchildren uh and when they interviewed about her about it she laughed so that doesn't fit my schema of Grandma um and she looked like a grandma right so what we might think a grandma would look like maybe I don't want to get in trouble saying this but you know maybe like a House Co an old old school 1950s house coat in the kitchen cooking bread all that kind of stuff and you wouldn't suspect that she would do these things and I think that's why we are maybe not so quick to catch femal serial killers and we're really not so quick to think yeah she did that and I have some stories for you if you would like about that type I would I would like yes oh my so I get some really interesting I can't say fan mail but attention from uh Lucy letby committed her crimes in the United Kingdom in in in Chester right Chester England um and Chesire United Kingdom Lucy leby was a neonatal nurse she was a very skilled nurse and she was was convicted last year 2023 of killing I think it was seven infants and I was asked to talk about that on on some podcasts and some other interviews in the United Kingdom well I got my Sher of colorful emails uh I'm wrong I'm try how could I ever be so stupid they made fun of my American accent thank you they said I must be in cahoots with the crown I'm like the only time I'm you know making a deal with the crown is when I'm binge watching the series on Netflix um you know what I'm going by is the evidence that the crown prosecution service presented that the jury convicted her on and that Justice Gau sentenced her by uh and also Lucy fits some of the parameters of previous data of known female serial killers so I'm just going by that but I've gotten all kinds of emails and notes and Twitter posts and stuff that tell me all kinds of things about me yeah what's the issue that people have with you coming at this from a very well I think you've got a thousand plus references of some kind in your book it's not like you're just making up some Whimsical dark story you're trying to assess this using the latest in scientific methods thank you for saying that so absolutely so I I mean I'm not I I'm not a popular media writer I I conduct academic research you're right in the book Jus as deadly I literally have 1,200 references uh and they're not like you know Zippy's blog of murder I go into academic papers I go into court documents I go into birth certificate Census records etc etc uh and my team and I gathered data to determine some of the quote unquote typical parameters of female serial killers and we came up with we put in a publication from 2015 published in the Journal of forensic psychiatry and psychology and So based on da all these data that we looked at we know some things about some female serial killers and Lucy fits those those so what would be my angle I I don't know know her I don't want to know her uh I'm just going by my you know quote unquote expert informed opinion and I'm going by the fact that a jury of her peers sat through that entire trial and weighed the evidence uh and just decided that she was the one who did this so I have no you know personal stake in the game other than to you know hopefully get Killers off the streets or better yet prevent it before it happens what were the criticisms that you were getting from the people that were uh tweeting things at you or or being critical of the work that you were doing um and what do you make of that motivation I imagine you've thought about why these people had such a visceral response to you just coming in to do analysis sure I I I'm not sure about okay so I can tell you what again they said I was uh Stupid blind uneducated I I I mustn't have looked at the correct data I must be on the side of the crown um I am half British but I'm a United States citizen I'm I'm down with the crowd they're cool but I have nothing to do with with the case that they presented uh and again they like I said they even said I they don't like my American accent okay well cheers cheers to that now why they would do that I mean people just when when somebody's convinced something is true they dig their heels in and even in the face of contrary evidence they might dig in even further and instead of addressing the message as you know an homon him attack they'll attack the person that that delivered the news I'm just giving an opinion now I also think I wonder seriously I wonder if I were a male researcher delivering this news if if the receipt of such and the response to such would be different I'm not sure that's interesting why do you think it is that the entire world it seems is so interested in serial killers I don't think I'd really growing up ever thought of that and then this sort of flourishing True Crime industry comes out especially in podcasts and audiobooks and now Netflix documentaries and my feed on Netflix is just filled with different murder mysteries from the 80s and the 90s and stuff uh why do you think this morbid curiosity comes from sure absolutely so I'm sure there are many many factors that go into why somebody might be interested in that phenomenon and the level to which somebody's interested in that phenomenon me coming from an evolutionary pers perspective because I'm a trained evolutionary psychologist uh just what you said morbid curiosity so I do believe morbid curiosity informs protective vigilance what does that mean we are pre-programmed to pay attention to the things that could hurt us like wow look at that right if anybody has ever heaven forbid past a traffic accident right paying attention to it can't keep your eyes off it I think we are literally genetically pre-programmed to pay attention to the things that could hurt us so that we can take in information and I do want add that this is very likely all unconscious right you're not going to say oh my goodness let me watch this latest uh documentary on John Wayne gasy so that I can make sure he doesn't hurt me he's dead right so I just think it's part of human nature to pay attention to the things that can harm us so uh I I started studying myself I started studying female serial murder or serial murder because I was interested in it I have traditionally studied romantic attraction between men and women um one of my friends uh Dr Thomas Bowers was conducting a project on mass murder and I said hey Tom can I be on your team I can add some evolutionary you know opinions to that yeah yeah yeah and then while I was doing that a really great student named Aaron came up to me and said Dr Harrison can we do an independent study on serial murder I'm like oh yes right I didn't even ask why or what or how or who or when yes let's do that because you know it's just so interesting but I'll tell you what as I got really into the topic years and years of research I I'm I'm really grateful for media Outlets seriously like yours and and there's some really authentic networks out there that want to uncover the truth but I do take exception to using the genre as some kind of morbid Museum like like dripping blood down the wall or whatnot and and and drinking alcohol while talking about victims that's just not I don't think that's very empathic to the victims and their their their families which and their friends which are considered co-victims yeah it I guess it turns a a crime into a recreation activity and you know you you forget I suppose the even with um Netflix now they're taking real cases and dramatizing them beautifully with attractive actors and it's shot very nicely um and that really does I never even thought of this before but it's a great point it blurs the line between something which actually happened and fiction and you go well it's a it's a true story yeah but I mean like was it as glamorous as this did everyone have super smooth skin and you know I don't know it's a it's a very interesting question to ask I I absolutely agree with you and I could tell you that I have a colleague um whose uncle was murdered and it is a well-known murder I don't feel the Liberty to to to say which one it was I'll let her tell that story um but she agreed to do a very popular podcast not yours Chris you're a good guy but she agreed to do a podcast and a uh the the the victim was involved in the entertainment industry and it it really did have good-looking people around and after the interview was done and my colleague spoke on behalf of the family they pumped in music to the Final Cut and said oh wasn't that a sexy murder now let me tell you that really hurt this person's family um the my colleague couldn't believe they did this they said I thought this was a legitimate interview and I was representing the interest of the family and so you tell me uh you know when I get asked to speak to the Murder Club and I kind of cringe I I just you know look to to each their own but I I do wish as a society we had more you know I I I wish we had more empathy for the victims then again I'm researching and I'm you know selling a book that describes it but I really truly hope I've I've put forth that message I'm trying to give out data out there so that we can respond to or better yet prevent these kind of things from happening what percentage of serial killers are female so no one really knows but the estimate is one out of six at least in the United States that's what I know about Y and how how many again whatever it is some joke about the only time it's a crime is when you get caught right but um of serial killers that we have either caught or whatever figure it is that we use as a total number how many is that per year what is what is one out of sixish are we talking about 10 people a year are we talking about one person a year that's a really good point I the the truth is I don't know but I can tell you female serial murder is very rare So since I've been studying this which is probably 2014 so probably the past 10 years the cases I've been asked to look at maybe three or four wow right so that's that's not historical right that's ongoing so in the last decade you found around about one was ongoing right I'm sorry I didn't mean to cut off Chris not at all so you had you would ask ongoing so since my research trajectory emerged there were about four cases that I became aware of for example R amaz in the United States Lucy let be in the United Kingdom um and there are I believe two more uh there was one a case that I actually consulted on that I probably can't talk about they they got her um they knew it was she they got her the true bill um ran jury indictment came out she knew this and she died by Suicide before they could arrest her go swinging a Miss it's it's true uh and I'm good friends with the lead detective on that I said how do you feel I just wanted the families to have Justice I said they did said you did your job yeah wow uh what is the let's get into the meat and potatoes of this talk to me about the demographic of female serial killers who are they so um is it okay if I refer to my paper here abely so we published a paper in 2015 where we took the data that we had the sample size we had was 64 female serial killers who committed their crimes in the United States really since there's been a United States so 200 and something years please don't make me do the math on that and here's what we came up with um she's likely white she's probably been married at least once but perhaps several times um probably in her 20s and 30s probably Christian probably middle class probably has committed her crimes in the suburbs um she's probably employed and there's a very good chance she's going to be a health care worker like a nurse or a nurse's assistant about 404 z% of female serial killers are nurses or nurses assistants uh we know that she's very likely in charge of taking care of helpless others so whether that's a mother or a nurse or a nurse's aid so somebody who's vulnerable and can't fight back a child an elderly person a disabled veteran Etc um she's probably at the very least of average attractiveness attractiveness or maybe even good-looking um probably had some childhood problems herself with abusive parents maybe some sexual Assa CSA childhood sexual abuse she experienced when she was younger um Etc um and the motives that we found um money was the number one motive so money resources but very close second to that was power and so let let me just say this if I could do this paper again if I could do this entire project again which took a long time to do I focused on primary motive and if I could go back and reinvent this I probably would have looked at multiple motives because I don't after all this knowledge gained uh over the years I don't think you can really split it out I don't know if money and power might go hand in hand I could just say numerically money was the number one motive and power was the number two motive when we looked at this person's primary motive okay let's get back to those demographics so they were moderately educated they um were gainfully employed typically um many were in uh marriages or in relationships so just immediately thinking to compare this to the sort of loner man on the street guy in a cabin solo Sigma male danger person the Ted Kinski of the world or the sort of Night Stalker person of the world this seems this seems like a big difference so using your evolutionary lens why is it simply that there's fewer female female homeless people is it that there's something the stasis and the foundation of a family gives a a female potential female serial killer the uh stability that they need to be able to go and commit a more uh outrageous crime what do you think oh sure I think everything what you everything you just said could come into play again I'm an evolutionary psychologist so I do look at sex differences um and we do see profound male female seral killer sex differences we wrote a paper on that um we published it in evolutionary Behavioral Sciences and we looked at stuff like for example men are far more likely than women serial killers of course to Target a stranger um women are far more likely than a male to Target somebody familiar to them again primary motive for men was sex primary motive for women was money men tend to be undereducated women tend to have at least some college that's not speaking to intelligence that's speaking to level of Education attainment um that just on ucation uh what do you think it is that's driving more uneducated men or more educated women to commit murder I'll give you my bro signs theory of why it might be uh from from my perspective um low status men have less to lose and socioeconomically uh if you know that you're a little bit further down the the hierarchy roll the dice whereas for women that's not as much of a drive right I think what you believe would play into what I believe in that a low status male is far less likely than a middle class or high class male to get a date or to establish a relationship and so this there's this aberant sex drive the other thing the other way we can look at it is like this and I haven't thought about this before but when you were you were talking it made me think is it somebody was undereducated or is is it somebody so pathological that they couldn't go through the educational system regardless intelligence right just kicked out of it right right so that just brings me to another male female serial killer sex difference which I'm not really sure I it it let me say this our data show that at least 90% 90% of male serial killers had some form of mental illness in female serial killers our data show that 40 40% had some form of mental illness now we could say wow men are twice as likely to be mentally ill but I'm not sure so sure right because we have to visit the salience of diagnostic systems over time whether this person actually was ever assessed I'm not sure in fact after conducting the research that I have after assembling research to write the book Justice deadly I'm convinced there has to be some form of mental illness present for somebody to commit these heinous crimes there must be they don't think like we do you and I wouldn't do these things to babies or elderly people or women mag in a library you've got to be thinking aberant so especially especially given what did we say at the very beginning this sort of Alo parenting caregiver typical mothering nursing type uh Trend that women have this predisposition that many women have at least on average in comparison with men that to me would suggest that in order to overcome that nature and do what is the opposite of caring for I mean think about little girls in a schoolyard right at least little boys practicing Warfare there's aliens or there's Cowboys or there's whatever that they're do they're Waging War on but what are the girls doing they're caring for something a small rabbit or a doll or whatever it might be we're playing hospital and you know Joyce Binson's done tons of this work this this happens really really early on in life right and okay that to me suggests that it's an even bigger jump from the uh set point let's say psychologically uh of females to get themselves to the stage where they're prepared to take a life sure absolutely so we do know that it's not you know not all boys play with trucks and planes and not all girls play with dolls but that's that's predominant I myself I played with stuffed animals it's all good right so but absolutely and we do know that in women to me it's undeniable there is a caregiving there's a caregiving Instinct in all of us but there is a caregiving Instinct um and so again I'm an evolutionary psychologist and what we say is that an evolutionary psych behavior is evolved because that behavior led to traits and dispositions that made you leave more descendants right so we have this caregiving thing people who had a caregiving um Instinct left more descendants but we also say in evolutionary psychology that there's this poly distribution of of inherited traits so I'm going to draw the bell curve for your your viewers right so if you took a statistics class remember the bell curve and let's say let's say moms most of or or even nurses right most of them are right in the middle the right amount of care giving let's let's go with Mom's the right amount of caregiving most of us turn out okay but if you look in the bell curve and you look down all the way in one tail you'll see the extreme people who are overbearing and over anxious and they monitor child's every single move and they get sick and to their stomach when their kid goes to the prom something like that all right that's one tail what about all the way in the other end of the other table tail sorry the other end of the other tail we have people who are abusive um people are neglectful and then deep down in that other end of that other tale we have people who kill their own kids right so there's this caregiving Instinct gone arai and I do believe that is the case now you mentioned something going back to nurses as female serial killers uh I actually have dated a nurse I've actually dated a neonatal intensive care nurse and when I told her about uh Lucy Ley she couldn't believe it she How could somebody who has devoted their whole entire training and life harm the person to which they took an oath that they would help so how does that happen and we don't really know I could say that right now not my research but some other research has suggested that I don't know if a nurse goes bad I think maybe sometimes that personality type goes into the field I don't know if it's to have the control I don't know if it's to save thyself I have the urge to kill people let me help them I'm not sure um but I do think maybe that kind of person goes into the field now that being said please let me say this almost every nurse or almost every mom that's ever lived and will ever live will never hurt somebody like that let alone become a serial killer we know that but that's just speaking to the extreme and that's the uh the research field that I've entered I wonder whether it's like a misfiring angel of Mercy thing if you can somehow convince yourself if you spent all of this time caring for young people or old people or something else that I don't know what do they say about like you in retrospect does it seem like they think they're doing something good are they doing it for pleasure like I don't understand the money that you get from killing a child or an old person okay so if and this this is really awful but I've read some you know I've created some case studies from from history and put the data together where there were people that let me give you an example there was a female serial killer in Connecticut United States uh at the turn of the last century so you know Civil War time in the United States and thereafter her name was Lydia Sherman and she was a serial killer she killed her own kids she killed her stepkids she killed several husbands gave them Arsenic and when she finally admitted yeah yeah I did this why did you kill your kids well you know my husband lost his job and the little kids couldn't really do anything they couldn't do anything for me they couldn't do anything for themselves so I got them out of the way she quote unquote hurried them into eternity was the quote so got getting them out of the way is that angel of Mercy in some weird you know reimagine terrible angle I I guess now in terms of nurses I have read cases where somebody say well they were sick I was doing them a favor yeah right but take for example the case of Kristen Gilbert who is a serial killer from Massachusetts United States in the midn maybe the late 80s midn up to the mid 1990s um there was one to say veteran she killed his name was Kenneth Kenneth cting he was a really nice guy he was in his 40s in the hospital she asked her supervising nurse if this guy dies can I leave early and go home and he wasn't on death store or anything and the supervisor said sure sure enough Kenneth died by the end of her shift she caused him to have a heart attack so that's just getting somebody out of the way so angel of Mercy maybe we have experienced that in our societ exci in times but I I I don't buy it who Mercy who you know whose Mercy are you defining whose Mercy are you executing yeah it's an interesting one the um single versus married thing does why do you think that uh again women is it just that on average women are more likely to be married than men at this age I I'm not sure that's a good question so why the so one one I guess reason at the four front would be that women can kill their husbands right so they're going to get married and they're going to kill him and they're going to take his insurance and his inheritance and everything else ride that out for a while get married again let's they kill him take his stuff get married again take his stuff uh the Lydia Sherman that I was telling you about her nickname was the Derby poisoner uh that's what she did she killed this husband I'll get him out of the way then she married an old Widow uh widower uh and he was dead within months uh then she married Mr Sherman who was fairly wealthy and she got him out of the way and attempted to collect the insurance money but she didn't get away with that one and they went back and Sol the other crimes so right that might be one reason for the multiple marriage marriages multiple targets um but what what I wanted to go back to if I can is right in the beginning you were describing well you know they're married they're sort of educated this you know um that's exactly who you wouldn't suspect right like if I said Chris describe somebody who's not a serial killer well Grandma who you know stays at home makes cookies maybe has had two marriages maybe has three kids you know goes to to church sells stuff at a bake sale goes to synagogue sells stuff at the bake sale you know that's the person you wouldn't suspect hiding in plain sight hiding in plain sight exactly right what about life events potentially contributing or priming female serial killers to be more likely or psychosocial factors this this is interesting so when I documented I I I did that analysis more uh thoroughly on female serial killers and we found everything from mothers who died when they were young abandoned them fathers who were abusive we found physical abuse sexual abuse emotional abuse uh so we did find that in female serial killers history to a degree greater than chance right so more so than someone in the general population would experience but let me tell you something that I don't necessarily have data on that I probably could gather data on but when I wrote the book just as deadly I put together about 27 different case studies um and I I try to write about the psychology and whatnot and what I did was I wrote about five men and then the rest were women and I wrote about the men to show just how different female serial killers are and I can tell you in almost every one of those cases that person was severely sexually abused when they were younger and I've heard people come out of the would workk and say no it's a myth that serial killers were sexually molested no it's not no it's not I have I have read this now again let me stress for people who have had that terrible thing done to them when they were kids almost everybody would never grow up and hurt somebody else let alone kill them but if you want to see a common denominator in both male and female serial killers you see this profound CSA childhood sexual abuse I I I've seen it in the data the interesting thing there is as you identified previously and as we're going to get into in a bit in terms of motives men a lot of the time are killing it's in and around sex sexually motivated in one form or another but for women that isn't but for both men and for women uh childhood sexual abuse is predictive of becoming a serial killer later in life so what that suggests to me is there is what seems to be most likely um childhood sexual abuse does not make men more likely to use killing as a sexual weapon because you have a split test which shows that women don't they still do so what is it doing the way that you see the world this uh reactivity toward aggression this requirement to use physical force in order to be able to enact your will it seems like that but I mean that's fascinating right that you basically have the same scenario both predicting the same outcome but the way that the outcome is deployed is motivated in a different way absolutely you you said that brilliant brilliantly you're absolutely right and when somebody experiences that violation when they're younger I mean it's shown in the the research that I don't conduct right definitely behavioral Neuroscience research your nervous system literally rewires itself so imagine somebody who is violated when they are a child certainly they are more reactive their nervous system is more sensitive to any kind of aggression etc etc um it's it's terrible it absolutely changes who the person is and you're right that and male serial killers again I don't study them as thoroughly as I do female serial killers but it is my understanding most are sex crimes and they might start out as experiencing a paraphilia so what that is is like an abnormal sexual interest maybe in in like I'm not saying it's abnormal do what you need to do but uh there are um psychological classifications that would say for example Shoe Fetish is abnormal Etc so it might start out with that and then it might eventuate to watching somebody get undressed and maybe that doesn't fulfill the the gratification or the fantasy uh so it it eventuates and and and escalating right sorry escalates right to attacking somebody so we see that there was somebody by the name of Jerome Bruto think it's Jerome brutas who was a serial killer and he started off with a shoe fetish then he started killing women and literally keeping their legs literally severing their body parts and keeping their legs sexually assaulting them and then keeping their legs to show off his shoe collection and so that's a really really worst case scenario right uh but but it it happened and again serial murder is rare and female serial killers are even you know rarer but it does happen do female serial killers take trophies that's really interesting so uh my colleagues and I uh Stephanie wink John black CLA alile and I are looking at that it's a study that we're currently working on we've not gotten it published yet but yeah we do see that males are you know very likely to keep trophies more likely than females are here's the thing I actually didn't think as many female serial killers would keep trophies but in the again these are new data we don't have them released yet but I did see that that they did now it depends on your definition definition of trophy if a male serial killer keeps it is it to you know being frank masturbate to it to relive the sensation the you know the sexual gratification of the crime it could be some kind of glorification you know totem and whatnot I found women they're going to keep they might keep like a necklace or a lipstick or something and I don't know if that's a trophy or that's because they like it right let's Okay this is a nice lipstick why should I throw it away so I'm not really sure about that but I saw trophy keeping in both sexes just a lot more in in male serial killers there's some other teams that say that they didn't witness that in the data but my team and I did find it in the data what about substance abuse I have seen that as well again I don't have those data in front of me but I have known cases of female serial killers who had drug abuse problems um there's one female serial killer who used to gosh I better not say a name because it's it's not coming to me right now but she would uh she was she had profound substance abuse she used to hide drugs in and she would wear her hair in curlers like how women curl their hair and leave the curlers in she would hide pills in her curlers and in her toilet paper in her bathroom she had a really profound substance to uh problem but I don't see that as like if you asked me to pull up my data from the 64 female serial killers we initially uh we initially studied I didn't really see that as a Salient Factor have you got any idea how common that is among male serial killers that they're drinking and killing or taking drugs and killing or that they're self-medicating from maybe some psychological disturbance I would guess again what we need to try and separate out here is what's the base rate difference right on average between the Sexes again more women are caregivers but probably not it shouldn't come out at 40% of them as being caregivers so that's not the you know what I mean I'm trying to no you're exactly right so I don't I don't know and you're right not only men male versus female serial killers but male serial killers versus men in general and female serial killers versus females in general so I I don't I don't know that I have seen because I've studied some people in depth like oh yeah she did that or yeah he did that but I I don't know the data overall um it seems to me though that would be not a cause but one of the effects of whatever went wrong initially pathologically trying to numb myself and then committing those crimes as well but I don't really see the drugs and alcohol as fueling the crime so that's a we have this psychological disposition maybe disturbance Downstream from that lots of things happen yeah one self-medication maybe drinking another one of them maybe being killing lots of people okay so let's let's get on to victims who do female serial killers kill what's interesting about that what's different about that okay so most commonly female serial killer will have both male and female victims most commonly a male serial killer will have female victims um but like we said before women tend to kill um elderly people people of you know of age infants or uh people with some kind of disability or illness that all of these people can't fight back that's the common denominator predatory sort of absolutely that's a good way to put it AB absolutely sure why why is that is that safety there's no retribution there's no there's no retribution and wouldn't one be less likely to be caught if somebody who was in the hospital for an illness dies right couldn't be attributed or explained away as a product of their illness or injury or a baby who dies I mean again I studied some female serial killer cases from back in the day it wasn't unusual for infants to die back then right there was a higher infant mortality rate um so I would think that the victims could be explained away um also for women who killed their husbands back in the day um it wasn't unusual for somebody to die of stomach disease and whatnot and so these women tended to use arsenic and other poisons that would mimic stomach disease um heart attack Etc so I think it's the the victims that people might not suspect are they ever sexually motivated from women that's a very good question I have not really seen that frequently I've heard anecdotally that maybe one or two might have had some sexuality going on there for example again I didn't see this in any official reports or newspapers or anything but there's some rumors out there that Jolly Jane toppin she was a nurse from Boston the Boston area uh United States from the turn of the last century like the 1900s and she used to give her patients central nervous system um stimulants and depressants to put them to the brink of death bring them back to life and she wanted to lay in bed and hug them as they died so she could feel the breath going out of them and there was rumors that she may have kissed some of them or mounted them that was just some some rumors but I've not really seen that officially corroborated I've read reports where she actually said I got into bed and held them to experience their last breath and she thought that was a glorious event so the power involved there is interesting what's the split of male to female victims for female Killers um that I'm not sure give me one second I'll look at my paper and see if I have that written down I'm just interested you know I'm wondering whether when you I'm wondering whether the split gets skewed when you get rid of children when you get rid of infanticide ABS oh that one I know for sure men are far less likely than women to kill children only far less likely I've seen it done but far far less likely that's a good question actually a women likely to kill young people like children than men are um let's see so in terms of killing only adult victims it's equal about 49% of male serial killers and about 49% of female serial killers both adults and children 47% male serial killers 23% female serial killers um only children about 4% of male serial killers and about 27% of female serial killers W so you've got the infanticide killer stuff going on there how much of that have you got any idea um again if you were to separate how often is it for a mother to kill her own child as part of a serial killing career and where infanticide is a thing that happens from mothers to children but doing it as a serial sure absolutely so going back to the definition of serial killers that we use three or more deceased victims with a cooling off period and use the term cooling off however you want just the time gap of at least one week between victims so we might have somebody a a mom with Munch Housen syndrome by proxy uh we call it these days factitious disorder imposed on another who would kill child after child year after year and they would be considered a female serial killer um how often that happens it does happen it's not very often there was a female serial killer named um Mary Beth tinning in skincity New York United States and it is suspected that she killed at least eight of her children I don't think she was convicted of all eight um but they The Story Goes they think that her first right The Story Goes that they think her first baby died natural causes and that maybe she saw all the attention she was getting and so the next baby and the next baby and the rumor was that she had some kind of nursing knowledge so she knew how to Mock and present symptoms uh and that she would back then even in the 70s and the 80s medical records were not as centralized as they were now as they are now so she would go to different hospitals with these different infants um there was a book written about her uh and the author of the book and I'm sorry the name es escapes me but it's a very good book she said that Reports say that at each funeral Mary Beth would get all this attention and she seemed to quote quote be having a good time at the funeral of the babies everyone saying oh my goodness what a poor mom what a good mom you are and finally somebody called the hotline Anon anonymously and said aren't you gonna do anything about this and they looked into it um and finally with the death of Tammy Lynn her last child um they they they caught on in fact Mary Beth allegedly tried to kill her own husband and he didn't even really do anything about it but child after child year after year so yes this person would be considered considered a female serial killer U let me add one thing about the Mary Beth tinning case it's the first modern case that I've been reading about these for 10 years now it's the first modern case where I saw the prosecution and the defense say wow there's something really mentally wrong with this individual they need help versus in the past in the 40s and the 50s I've seen you know ret retribution like let's put this person to death in this case I've seen wow you there's some got to be something really wrong for somebody to do this let's try to get her some help this the first kind of compassionate case I saw again I'm not trying to say I feel bad for serial killers but if you know some things have happened to these people and if I may if I may just add this Chris um I it's tough because I'll give talks and I'll say there are some serial killers I I feel bad for and I I don't want that take out of context and then get canceled over it because I have really a lot of empathy for the said much worse things on this podcast there's much okay it's good but let let let me say this let me tell you a story what if I told you a story of a young boy who um his father named him a very masculine name but it turned out he was a little bit feminine so the father used to beat the crap out of him beat him in the head till he was unconscious this boy was molested when he was a at age five by a female babysitter little bit later when he was about eight years old he was molested by a male local contractor and his sister corroborated these things um his mother was so physically abused that the father would beat the hell out of both the Son and the and the mother I wonder if somebody would feel sorry for that person I I do right but that person is John Wayne gasy so if I said to you do you feel bad for John Wayne gy by the way he killed at least 33 young men and buried their remains under his house and threw them in the room ever you don't feel bad for that but if I told you the story of that boy that they called Johnny back then you'd say oh my gosh right now again most people were abused never ever would harm somebody like he did but we look at that and we say wow you know if somebody had come in there and helped Johnny and his mom maybe those 33 young men would still be alive so I think that's you know something yeah we want to solve crimes but as a psychologist let's solve the psychology let's Solve the Riddle and we can get in there maybe help people before they go down this path can we talk about the the motives but using an evolutionary lens understanding so you said money right power right uh and then give an evolutionary perspective to that and then can you compare that as well with uh the male motives absolutely so uh I'm an evolutionary psychologist by training actually my degree says biopsychology but I'm an evolutionary psychologist it all comes down to sperm SPM and eggs all right it always does so men produce millions of sperm on a daily basis women have all they're born with all the eggs they'll ever use they'll probably only ovulate maybe a couple hundred times in their lifetime so if you look at reproductive potential men could father as many people as they could find reproductive Partners women you're only going to get pregnant once right so men have a lot more chances for reproduction compared to women men have higher sex drive compared to women worldwide I'm not saying you're going to meet a woman who's not the horniest person you've ever met in your lifetime I'm not saying that but on average men have far greater sex drive than women do and we in evolutionary psychology attribute that to underlying biological differences okay so how does that play into serial murder like okay so women with these very limited eggs very limited reproductive opportunity in the ancestral environment it would have benefited a female to pair with somebody who had a lot of resources right because not now right we are women here as roora but back in the ancestral environment you females were far more slender and helpless and whatnot it would have been really reproductively Advantage advantageous to pair with the alpha male who had a lot a lot of access to resources in territory so men seek sex women seek money worldwide women prefer people with resources what are the number one motives for seale for for serial killer sorry about that one more time what are the number one motives for for serial murder for men it's sex for women it's money that didn't surprise me at all absolutely not and then there was another perspective that I had and it takes a little bit more you got you gotta bear with me on this one but my team and I came up with the hunter gatherer hypothesis of Serial murder and it's not the only explanation trust me but it could be a part of the explanation for serial murders in that it is thought that anthropologically speaking we evolved from societies where men did the huning and Men did the hunting and women did the Gathering right and so what do we see male serial killers as Hunters they stalk victims unfamiliar victims they write down their times of day and and where they work and their friends and they follow them just like a hunter would hunt prey and they keep trophies right like a hunter does women it's you know this one a little bit more figuratively they gather victims they gather the people around them they look around who is around me let me kill them and then they gather prophets as well so we did come up with a hund gather hypothesis and we everything we tested in our study we you know showed to be to be so so men Target strangers they kill people outside their birthplace uh etc etc um so there is some evolutionary perspective but let me add I know it is not the only fact you have to consider developmental um components developmental trajectory parents school um childhood illness Society gender rules you know time in history you have to consider all of these things to to think about what makes a Serial murderer but I do think there's an evolutionary component yeah it's it's interesting because you always hear that um a a wife was killed where's the first place you look the husband right well by evidence it seems that men are more likely to kill strangers than they are to kill their intimate partner that is interesting however the number one motive last time I checked in North America for murder was male perpetrated jealousy so there you get the intimate female partner male perpetrated jealousy what's that yeah so I'm sorry so a man kills a woman because he's jealous of something last time I checked the statistics I might want to go back and check the statistics but in North America Jed rejected I'm falling in status I my woman is cheating on me that kind of thing or I think she's cheated on me uh and David bus and colleagues have done a lot of research on that how do women kill what are their methods of choice poison so I a lot of people call those passive methods I'm not sure uh if you've ever read about what arsenic does to somebody's body chronic and acute what do it what does it do let's say I take some arenic oh my gosh let's say you take some arsenic well you're going to get in sephtis your your brain is going to swell all of your internal organs are going to swell and then fail your your gastrointestinal system is going to bleed you are going to vomit blood you are going to have bloody diarrhea you are going to be doubled over in cramps until you die so we don't want don't we don't want anybody to do that it's horrible it's painful and it might not even be that day it might be days of this person's suffering it's horri what so poisoning a variety of different ways that they use it I'm going to guess right yes and so I I say poisoning but I use actual poisoning like tarot rat killer ant killer that kind of thing arsonic that used to be able to buy just you know buy the ounce at the uh the Apothecary back in the day and prescription drugs so they might inject somebody with insulin and induce a heart attack and then they die by heart attack and if they're in the hospital anyway and say oh wow hey he had a heart attack then people might not suspect it so uh yeah so it could be poison in terms of illegal used poison or Pharmaceuticals used uh to a poisonous uh efficacy I wonder if much of the reason that you have this higher prevalence of of caregivers and nurses is simply that they're around the weapons that they're going to be able to use it it could very well be so I have a good friend who is a nurse Somebody went to high school with and she's been a clinical nurse 25 30 years and I called her I said why right why and she said mariss don't take this the wrong way but right now I can tell you a hundred ways I can kill you and no one would ever know she goes that's one thing that comes to my mind she Sayes no one would know we know how to do these things though I they so they have the means and the access and again if somebody dies in a hospital it's not the most peculiar thing that's ever happened so they they the means to get sight yet exactly what oh you've spent all of this time studying a lot of female serial killers of all of them who has been the most outlier psychologically that you found I would say the outlier is I would say the outlier is Eileen wore on us because she shot men uh left their bodies in the Woods to to decompose and Rob them I mean so you have the financial motive there but I mean she was really abused she had some mental illness she was a psychopath etc etc so I don't know if she was really the outlier there um again I think even in the absence of any diagnosis that I have read you've got to be mentally ill to do something like this so I don't know if there's any psychological outliers but if you name a mental disorder I have seen it in serial killers uh female serial schizophrenia bipolar disorder uh anxiety disorders Munch hous and syndrome by proxy now called factitious disorder and post on another so if you name it it's a Bine personality disorder it's represented in serial killers what about female serial killer wives of male serial killers like killer couples interesting so I never studied killer couples and I'll tell you why I wanted to study psychology and I wanted to know the what called the autogenic motive like coming from you so if this is my husband and we're killing how do I know who it came from how do I know who who thought of these things or who persuaded whom to do what I don't know so I never studied paired serial killers there is a pair I'm thinking about I've not studied them but the pair from the United Kingdom was it Ian and sorry Mira Headley is it yes okay right so what's really interesting about them and I'm just maybe go on off a little tangent here but please follow me I don't even really remember his last name but I remember her and from what I recall and I've had I have some friends from Britain have some family from Britain they tell me she is one of the most hated people in Britain I'm like yeah but what is wasn't it Ian's idea and they're like yeah but people hate her why I think because she violated the female role she was a good-look woman who enticed kids to go on on a journey whatever those awful people did to those kids and and people hate her more for being the accomplice than they hate him for coming up with the crimes he chops somebody up with an axe right but they hate mirley the number one it feels like she's contravened some sacred sort of protector code it's almost like I I guess again it's sort of the public perception thing that men we we expect that men are more likely to be serial Killers so when you see a woman assisting a man in doing something you already know as heus you feel like it's almost double heus in a way oh absolutely they they really do I just don't want to get her her name wrong Mera hendley that's it because people say there's the lady that wrote the book but doesn't know who Mera hendley is all right talk to me about the sociocultural environment that we've got at at the moment um and uh sort of living setup again if you're taking an evolutionary lens with this we are in a novel environment uh ancestrally right now right what do you make of that for the uh persuasion or dissuasion of uh Killers male and female uh the thing is I don't think it is so again I've studied female serial killers uh at length compared to my study of male serial killers which I've studied somewhat and they got away with it largely because their methods were undetected for a long period of time I think we have increasingly sophisticated medical examination techniques medical recording systems I mean somebody who kills somebody if they died of arsenic poisoning we're going to know on the first try so I really think that's going to dissuade female serial killers that being said that's the kind we're used to I don't know there might be some kind of woman that does these things and gets away with it that we haven't caught or written about now in terms of male serial killers in terms of the typical profile of uh stalking and killing strangers I I'm not sure uh think about the victims being so interconnected in this day and age with social media and and I'm tagging myself here and I have cameras all over my house I'm not so sure it would be easy to to get away with that and again to meet the criteria for serial killer it would be three or more victims with a cooling off period of one week between or a timeout of at least one week in between so even if somebody was horrible enough and stupid enough to kill the first person are they going to be able to get away with it the second and the third time yeah I I really think about this a lot especially given my nighttime ponant for watching Netflix true crime documentaries and stuff like that uh so much of this is you know it's 60s it's 70s it's 80s it's it's out west somewhere in Alabama or whatever the [ __ ] it is that going on and I was like why I don't hear much about modern day serial killers is that just that forensic techniques are so good that one potential serial killers are much more dissuaded from starting or two they're so good that after the first or perhaps the second they don't get chance to get to the third because they've been popped by some great investigator like your friend the detective right it it could very well be I I I think you're you're on to something you're absolutely right and also I mean what about internet detectives right put a picture on on on Facebook or or Twitter and say catch this person they did X they're caught in 20 minutes right so I I think you really can't get away with stuff these days I wouldn't even try I wouldn't I wouldn't recommend it so I do think the detective work and the science is there to prevent or at least catch before someone eventuates to the level of Serial murderer that being said let let let's hope not and I also know that if people really want to do something awful they will I don't want to go down this slippery slope but honestly um there are mass murderers who if they don't have guns they set a house on fire or they push a car in front of train they'll stab you they'll find a way right so um I wonder so this is we're we're an hour deep so I can say all of the spicy things now you know how there is some good evidence that uh women commit or attempt should I say suicide uh more than men but men are more for want of a better word successful they they complete at a higher rate I wonder whether and this could go either way it could be men or women uh men or women are less successful at not being caught as serial killers you would imagine there's sex differences in everything pretty much uh so let's say for instance uh I would guess on average that females are more likely to be better at hiding their tracks being conniving planning uh doing that sort of stuff so maybe the uh one in six number is that they are over represented because their failure rate the amount of times that they kick some invisible trip wire that a man who being a little bit more clumsy less planned out less sort of calculated in the way that he goes about his serial killing Ventures uh I get the sense that maybe they're over represented because they're actually quite good the that disposition helps them absolutely so it's it's interesting I collected those data twice and once uh the data showed that women got away with it longer and then the second time I did another study it was just about equal and I have those data in front of me the killing span we called it the mean years killing for men was 8.7 years for women it was 7.8 years so just about just about equal uh so they get away with it but but you're right I mean if somebody is leaving this if a male serial killer is sexually assaulting victims and leaving this trail of you know unfortunate dead bodies around the town you're going to say whoa there's somebody there let's catch them they're gonna work really hard at it uh versus female female serial killers if there's this is awful but babies dying in a hospital it takes somebody to go hold on wait that's there's a statistically a statistical anomaly somewhere let's go back and check it out people don't just normally turn up with axes in their heads but babies do sometimes die in hospital yeah exactly exactly right um so it it seems like we have to catch a male serial killer but we have to detect a female serial oh that's so great and I think there's a difference there how cool is there anything else that we haven't said from the sort of evolutionary lens perspective thing around female serial killers any unclosed Loops I I think just I I'd like to to close up wi with this and it might not be evolutionary but you know I conducted research to be able to write my book with Cambridge University press but then I learned from writing the book right and I know for sure from the data that I've seen and from the case that I worked on that we need more police resources right so the world is not like CSI where you send data you know you send specimen down to the lab and my friend from the FBI says it's hot men and women analyzing DNA to a banging Musical soundtrack right the world doesn't work like that they need money for these tests they don't the police organizations sometimes don't have these we need more money for police and detective work we need more of it secondly we need more psychologists right because let's say somebody intervened back in the day Eileen ronos was so sexually abused in reap when she was younger she she accidentally got set on fire her grades went down in school and the the school called and said hey can we give her counseling nope right well some if she got a caseworker maybe things would have been different for those seven or eight men that she killed right so we need more psychologists to get out there and intervene because if something bad happens to someone the earlier you get there the better according to psychological data you can treat trauma if at all you could give a better shot at it when the when it happens if somebody's a kid when you get right there and do it right then and there so we need more psychologists and we we need more we need more psychologists and we need more police resources uh and that might tackle the problem well you may have inspired some fledgling criminal psychologists or detectives to get into the world of female serial killers today I I hope so I hope hope they take what what my team and I have done and and do it on a grander scale and and create change you know make you know stop crime help people where they need it I really hope so and thank you for saying that I appreciate you Marissa Harrison ladies and gentlemen Marissa where should everyone go they want to keep up to date with the stuff that you're doing oh you can check out my faculty web page Penn State Harrisburg or you can take a look at my book uh justice deadle the psychology of female serial killers Cambridge University press 2023 but the paperback edition is coming out soon so it's available at any retailer thank you so much congratulations I appreciate you thank you thank you Chris thank you very much for tuning in if you enjoy that episode there is something else you will absolutely love right here go on give it a tap