Research on Father-Daughter Child Molesters: Implications for Explanation and Assessment

1. Research on Father-Daughter Child Molesters: Implications for Explanation and Assessment Grant T. Harris and Marnie E. Rice www.mhcp-research.com 6th Annual Law & Mental Health Conference sponsored by CAMH and CSAMD May 3, 2002 (2002) Journal of Abnormal Psychology, 111, 329�339 -What we�re talking about is a kind of incest that virtually no one would condone or joke about-What we�re talking about is a kind of incest that virtually no one would condone or joke about

2. Canada Marriage Act (1867-1991) A man may not marry his: Daughter Granddaughter Sister Mother Grandmother Aunt* Niece* Whether by the whole or half blood -Incest laws are related to marriage laws Canada�s law has its roots in English law dating from around 1563, during the reign of Henry VIII, a man who had more than a passing interest in the subject! Father-daughter and brother-sister marriages are forbidden virtually everywhere. But otherwise, there is great variability. First-cousin marriages are forbidden in some societies but are obligatory in many others. -Also, several non-blood relationships: -Ex-Wife�s grandmother -Grandfather�s Ex- wife -Ex-Wife�s mother -Ex-Wife�s aunt (I�ll bet these were popular!) Ask audience -Step-mother -Ex-Wife�s daughter -Ex-Wife�s granddaughter -Son�s Ex-wife -Grandson�s Ex- wife -Nephew�s Ex-wife In 1991, all of these non-blood relationships became legal in Canada, and the bottom 2 blood relationships-Incest laws are related to marriage laws Canada�s law has its roots in English law dating from around 1563, during the reign of Henry VIII, a man who had more than a passing interest in the subject! Father-daughter and brother-sister marriages are forbidden virtually everywhere. But otherwise, there is great variability. First-cousin marriages are forbidden in some societies but are obligatory in many others. -Also, several non-blood relationships: -Ex-Wife�s grandmother -Grandfather�s Ex- wife -Ex-Wife�s mother -Ex-Wife�s aunt (I�ll bet these were popular!) Ask audience -Step-mother -Ex-Wife�s daughter -Ex-Wife�s granddaughter -Son�s Ex-wife -Grandson�s Ex- wife -Nephew�s Ex-wife In 1991, all of these non-blood relationships became legal in Canada, and the bottom 2 blood relationships

3. Canada Marriage (Prohibited Degrees) Act No person shall marry another person if they are related lineally by consanguinity or adoption as brother or sister by consanguinity, whether by the whole blood or by the half-blood; or as brother and sister by adoption -in 1991, got a new marriage act-in 1991, got a new marriage act

4. What is incest? Legal definition: Criminal Code of Canada Every one commits incest who, knowing that another person is by blood relationship his or her parent,child, brother, sister, grandparent or grandchild, as the case may be, has sexual intercourse with that person. (�brother� and �sister� include half-brother and half-sister) Research/clinical definition: No need for blood relationship No need for sexual intercourse Research mostly involves children < approx. 16 Universality of incest taboos -Incest avoidance is a fundamental organizing principle of every human societyUniversality of incest taboos -Incest avoidance is a fundamental organizing principle of every human society

5. Human Incest: Frequency (legal) Overall, how prevalent is incest? Depends how we define it, of course, and how we measure it. But it is thankfully relatively rare in the general population. Toronto 1994-1996 2736 sexual assault incident reports, only 65 instances of incest. Of course, no number except 0 is small enough. --incest charges in 1961 in England and Wales-- Remember, we�re talking about the criminal definition of incest here! --notice how few are mother-son and none are grandmother-son!Over a 10 yr. Period, there were in all 15 trials of females for incest as against 1372 males!Overall, how prevalent is incest? Depends how we define it, of course, and how we measure it. But it is thankfully relatively rare in the general population. Toronto 1994-1996 2736 sexual assault incident reports, only 65 instances of incest. Of course, no number except 0 is small enough. --incest charges in 1961 in England and Wales-- Remember, we�re talking about the criminal definition of incest here! --notice how few are mother-son and none are grandmother-son!Over a 10 yr. Period, there were in all 15 trials of females for incest as against 1372 males!

6. Frequency of Incest Sariola & Utela 1996 (Child Abuse & Neglect) Finland 9000 15 yr. old girls .5% (1 in 200) .2% biological fathers (2 in 1000) 3.7% stepfathers (37 in 1000) Feelings of girls -As a recent example, a study of 9000 15 yr. olds in Finland were asked to fill out a questionnaire about father-daughter incest anonymously. The majority (93%) responded in the privacy of the nurse�s office, the rest in their classrooms. Almost everyone participated. Girls reporting sexual experiences with their father or stepfather was .5%. -- i.e. 1 in 200. Girls reporting experiences with their biological father was .2%-- i.e. 2 in 1000. However, 3.7% of the girls living with a stepfather reported sexual experiences with him. -So, the incidence of step-father-step-daughter incest is much higher than father-daughter -Contrary to what many fathers or step-fathers say, the feelings of the girls about these experiences were overwhelmingly negative. -Why are stepfathers so much more likely to sexually abuse their stepdaughters than biological fathers? -Common explanation had been that biological fathers had a specific �incest avoidance mechanism�-- Perhaps the fact that they took care of daughters from a very young age and that meant they didn�t develop a sexual interest in them -As a recent example, a study of 9000 15 yr. olds in Finland were asked to fill out a questionnaire about father-daughter incest anonymously. The majority (93%) responded in the privacy of the nurse�s office, the rest in their classrooms. Almost everyone participated. Girls reporting sexual experiences with their father or stepfather was .5%. -- i.e. 1 in 200. Girls reporting experiences with their biological father was .2%-- i.e. 2 in 1000. However, 3.7% of the girls living with a stepfather reported sexual experiences with him. -So, the incidence of step-father-step-daughter incest is much higher than father-daughter -Contrary to what many fathers or step-fathers say, the feelings of the girls about these experiences were overwhelmingly negative. -Why are stepfathers so much more likely to sexually abuse their stepdaughters than biological fathers? -Common explanation had been that biological fathers had a specific �incest avoidance mechanism�-- Perhaps the fact that they took care of daughters from a very young age and that meant they didn�t develop a sexual interest in them

7. Theories of Incest Freudian theory Close kin are desired as mating partners by most humans and �the desire for incestuous relations promotes the necessity for stern prohibitions� �Psychoanalytic investigations have shown... that an incestuous love choice is in fact the first and regular one, and it is only later that an opposition is manifested toward it, the causes of which are not to be found in the psychology of the individual� -Has led to the popular view that there had to be strict laws against incest or it would be rampant-Has led to the popular view that there had to be strict laws against incest or it would be rampant

8. Evolutionary view of incest avoidance Modern evolutionary theory Degrees of Relatedness 100% (Identical Twins) 50% (1st degree) Parent-Child; Siblings 25% (2nd degree) e.g.,Grandparent-Grandchild, Uncle-Niece, Half-sibs <25% e.g., 1st cousins share 1/8 of genes (3rd degree) Offspring of incestuous matings? -Introductory slide- View I�m going to adopt for this talk is an evolutionary view - Human beings are �gene-machines�. To put it crudely, our ONLY purpose in life is to carry out the orders of our genes-- and those orders are to get as many of our genes into the next generations as possible. However, because our close relatives also carry our genes, natural selection has designed us to maximize not only our own reproduction, but rather the replication of our genes through our own descendants AND those of our close kin. -Consanguinity= shared blood Identical twins share 100% of their genes. From an evolutionary point of view, if you�re an identical twin, it�s just as important that your twin reproduce as that you do. Assuming that the parents are unrelated by blood to one another: -1st degree relatives - parent-child and brother-sister share 50% of their genes -2nd degree relatives - grandparent-grandchild, half-siblings, uncle-niece -In all other blood relationships, the relatives share less than 25% of their genes. -However, in reality, humans, like other animals, prefer to mate with individuals who are quite similar to themselves. So, in reality, the percentage of shared genes is somewhat more than we�ve stated. -What about incestuous matings then? If the organism�s goal is to get as many of its genes as possible into the�. Father-daughter, mother-son, brother-sister matings would yield offspring with 75% of their parents genes rather than just 50%.. That is, offspring of incestuous matings carry more of their parents genes than offspring of unrelated parents.Many plants produce by asexual reproduction-�offspring� have 100% same genes as parents. Same would be true if identical twins could mate with one another and produce offspring-- but, of course, they can�t . Well, then wouldn�t incest be a good thing from an evolutionary point of view? -Introductory slide- View I�m going to adopt for this talk is an evolutionary view - Human beings are �gene-machines�. To put it crudely, our ONLY purpose in life is to carry out the orders of our genes-- and those orders are to get as many of our genes into the next generations as possible. However, because our close relatives also carry our genes, natural selection has designed us to maximize not only our own reproduction, but rather the replication of our genes through our own descendants AND those of our close kin. -Consanguinity= shared blood Identical twins share 100% of their genes. From an evolutionary point of view, if you�re an identical twin, it�s just as important that your twin reproduce as that you do. Assuming that the parents are unrelated by blood to one another: -1st degree relatives - parent-child and brother-sister share 50% of their genes -2nd degree relatives - grandparent-grandchild, half-siblings, uncle-niece -In all other blood relationships, the relatives share less than 25% of their genes. -However, in reality, humans, like other animals, prefer to mate with individuals who are quite similar to themselves. So, in reality, the percentage of shared genes is somewhat more than we�ve stated. -What about incestuous matings then? If the organism�s goal is to get as many of its genes as possible into the�. Father-daughter, mother-son, brother-sister matings would yield offspring with 75% of their parents genes rather than just 50%.. That is, offspring of incestuous matings carry more of their parents genes than offspring of unrelated parents.Many plants produce by asexual reproduction-�offspring� have 100% same genes as parents. Same would be true if identical twins could mate with one another and produce offspring-- but, of course, they can�t . Well, then wouldn�t incest be a good thing from an evolutionary point of view?

9. Incest avoidance among non-humans Animal studies Many animals avoid incest by juvenile dispersal sex differences in the age of maturation lack of sexual interest in individually recognized relatives Mammalian Examples Rhesus monkeys Deer mice Prairie dogs Juvenile dispersal = young all move away, or 1 sex moves Most mammals have incest avoidance mechanisms -Rhesus monkeys: When a male rhesus monkey matures, he will copulate with females of the same age as his mother, but not with his mother -Deer mice: If individually caged at weaning and subsequently placed in opposite-sexed pairs at maturity, littermates are considerably more reluctant to mate than are strangers -Prairie dogs: In nature, a yearling female prairie dog will come into estrus in the absence of her father but will delay first estrus if he is still around Juvenile dispersal = young all move away, or 1 sex moves Most mammals have incest avoidance mechanisms -Rhesus monkeys: When a male rhesus monkey matures, he will copulate with females of the same age as his mother, but not with his mother -Deer mice: If individually caged at weaning and subsequently placed in opposite-sexed pairs at maturity, littermates are considerably more reluctant to mate than are strangers -Prairie dogs: In nature, a yearling female prairie dog will come into estrus in the absence of her father but will delay first estrus if he is still around

10. The puzzle of father-daughter sexual assault Deleterious effects of inbreeding Especially among first and second degree relatives Costs to females versus costs to males -Inbreeding depression: Abundant data from many animal species including humans demonstrate that matings of close relatives produces offspring of reduced fertility and viability...Everyone carries a few rare deleterious recessive genes that are not normally expressed, and some of these rare recessives, duplicated by immediate descent in close kin, become homozygous in the progeny of inbreeding�. There is also an increase in close kin in the variance of the genetic liability to multifactorial conditions, thus increasing the risk of common congenital malformations and of mental retardation ..Thus, there is a substantial selection pressure in natural populations to avoid inbreeding�Studies of parent-child and brother-sister incest among humans show that they are very much more likely than offspring of unrelated parents to suffer abnormality, mental retardation,and death. Offspring of 2nd degree relatives, much less but still lots higher than unrelated. By the time we get to 3rd degree (eg. 1st cousins), not much elevated over unrelated. So, is it just a coincidence then that marriage laws tend to draw the line at around 3rd degree relatives? True even in societies who don�t know what the data say.. -And the cost of incest to females is much higher than for males. Because males can mate an almost unlimited number of times, he can afford to engage in risky sexual behaviors- risky, that is, from the point of view of the likelihood of producing offspring who themselves survive to reproduce. He can afford to engage in incestuous matings-- if the offspring survive to reproduce, he has gained a lot. If not (or even if so) he can engage in other nonincestuous matings where the offspring have a greater chance of survival to reproduce -But for females, incestuous matings are very costly as she can only have a limited number of pregnancies and can only rear a very limited number of children. So, more reason for females to avoid incest than for males -Inbreeding depression: Abundant data from many animal species including humans demonstrate that matings of close relatives produces offspring of reduced fertility and viability...Everyone carries a few rare deleterious recessive genes that are not normally expressed, and some of these rare recessives, duplicated by immediate descent in close kin, become homozygous in the progeny of inbreeding�. There is also an increase in close kin in the variance of the genetic liability to multifactorial conditions, thus increasing the risk of common congenital malformations and of mental retardation ..Thus, there is a substantial selection pressure in natural populations to avoid inbreeding�Studies of parent-child and brother-sister incest among humans show that they are very much more likely than offspring of unrelated parents to suffer abnormality, mental retardation,and death. Offspring of 2nd degree relatives, much less but still lots higher than unrelated. By the time we get to 3rd degree (eg. 1st cousins), not much elevated over unrelated. So, is it just a coincidence then that marriage laws tend to draw the line at around 3rd degree relatives? True even in societies who don�t know what the data say.. -And the cost of incest to females is much higher than for males. Because males can mate an almost unlimited number of times, he can afford to engage in risky sexual behaviors- risky, that is, from the point of view of the likelihood of producing offspring who themselves survive to reproduce. He can afford to engage in incestuous matings-- if the offspring survive to reproduce, he has gained a lot. If not (or even if so) he can engage in other nonincestuous matings where the offspring have a greater chance of survival to reproduce -But for females, incestuous matings are very costly as she can only have a limited number of pregnancies and can only rear a very limited number of children. So, more reason for females to avoid incest than for males

11. Four explanatory factors Pedophilia Failure of incest avoidance mechanism Mate deprivation & opportunism Psychopathy 1. Preference for sexually immature children: It has commonly been considered that IF cm�s are not pedophilic but offend for other reasons. Is empirical support for view that IF cm�s are less sexually deviant than EF cm�s, even tho� they may be different from nonoffenders. On the other hand, there are also several studies that show IF cm�s have preferences no different from those of other cm�s. Although pedophilia itself requires an explanation because a preference for reproductively nonviable targets is biologically costly, maybe FD incest is just 1 manifestation of pedophilia. 2 .Inbreeding increases the expression of deleterious recessive genes. Cost higher for females than males. A proximal explanation for the avoidance of incest is the Westermarck hypothesis according to which persons raised together from early childhood have an aversion to sexual intercourse with one another. Originally suggested more than a century ago to explain incest avoidance among siblings, there is some suggestion that early caretaking of a young daughter also inhibits paternal incest�.Seto et al. 3. Mate deprivation and opportunism: Men deprived of sex with their preferred age-gender category target individuals from the next most preferred category, especially if they are easily available and unlikely to resist. IF offenders frequently report disturbed family relationships in which daughter becomes a surrogate sexual partner. This has traditionally been the most commonly accepted view of FD incest. Fits with finding that incest offenders often found to have less deviant preferences than other cm�s. Pre-pubescent girls are at least somewhat sexually attractive to most heterosexual males, while child males are generally not. The mate deprivation and opportunism theory thus fits with the finding that pre-teen and young teen daughters are much more likely to be molested than sons even tho� EF cm�s frequently target boys. Doesn�t explain why fathers would incur reproductive costs of sexual contact with 1st--degree relatives instead of other extrapair copulations th� without adding factors such as social incompetence. 4. Psychopathy: Psychopaths --impulsive, opportunistic, sexually promiscuous, callous, lacking in empathy. Sex offenders higher in psychopathy than other violent offenders, and deviant sexual interests appear to correlate with psychopathy. Sexually deviant psychopaths at very hi risk of recidivism. Are FD cm�s psychopaths? On the 1 hand, would expect psychopaths to be abusive parents- maybe sexually abusive too. On the other hand, exclusive FD cm�s have lower rates of sexual or violent recidivism than other cm�s. Perhaps psychopathic FD cm�s offend against both their own and other girls.1. Preference for sexually immature children: It has commonly been considered that IF cm�s are not pedophilic but offend for other reasons. Is empirical support for view that IF cm�s are less sexually deviant than EF cm�s, even tho� they may be different from nonoffenders. On the other hand, there are also several studies that show IF cm�s have preferences no different from those of other cm�s. Although pedophilia itself requires an explanation because a preference for reproductively nonviable targets is biologically costly, maybe FD incest is just 1 manifestation of pedophilia. 2 .Inbreeding increases the expression of deleterious recessive genes. Cost higher for females than males. A proximal explanation for the avoidance of incest is the Westermarck hypothesis according to which persons raised together from early childhood have an aversion to sexual intercourse with one another. Originally suggested more than a century ago to explain incest avoidance among siblings, there is some suggestion that early caretaking of a young daughter also inhibits paternal incest�.Seto et al. 3. Mate deprivation and opportunism: Men deprived of sex with their preferred age-gender category target individuals from the next most preferred category, especially if they are easily available and unlikely to resist. IF offenders frequently report disturbed family relationships in which daughter becomes a surrogate sexual partner. This has traditionally been the most commonly accepted view of FD incest. Fits with finding that incest offenders often found to have less deviant preferences than other cm�s. Pre-pubescent girls are at least somewhat sexually attractive to most heterosexual males, while child males are generally not. The mate deprivation and opportunism theory thus fits with the finding that pre-teen and young teen daughters are much more likely to be molested than sons even tho� EF cm�s frequently target boys. Doesn�t explain why fathers would incur reproductive costs of sexual contact with 1st--degree relatives instead of other extrapair copulations th� without adding factors such as social incompetence. 4. Psychopathy: Psychopaths --impulsive, opportunistic, sexually promiscuous, callous, lacking in empathy. Sex offenders higher in psychopathy than other violent offenders, and deviant sexual interests appear to correlate with psychopathy. Sexually deviant psychopaths at very hi risk of recidivism. Are FD cm�s psychopaths? On the 1 hand, would expect psychopaths to be abusive parents- maybe sexually abusive too. On the other hand, exclusive FD cm�s have lower rates of sexual or violent recidivism than other cm�s. Perhaps psychopathic FD cm�s offend against both their own and other girls.

12. Seto, Lalumi�re, & Kuban (1999) Participants - female victims only 294 �incest� offenders 70 biological father incest 87 extended biological family incest (eg.nieces, cousins, granddaughters) 73 step-father incest 64 mixed incest (both familial and extra-familial victims) 254 extrafamilial child molesters 101 heterosexual controls Hypothesis -`Also included rapists but I�ve left them out for simplicity Hypothesized that biological fathers would show most deviant preferences. Why did they hypothesize this? Because in order to overcome incest avoidance mechanism, must be very deviant - What did they find?-`Also included rapists but I�ve left them out for simplicity Hypothesized that biological fathers would show most deviant preferences. Why did they hypothesize this? Because in order to overcome incest avoidance mechanism, must be very deviant - What did they find?

13. % with deviant preferences 3 slides 1. Results did NOT support hypotheses- Biological fathers were least likely to be deviant Not surprisingly, fathers who molested children inside and outside the home were the most deviant Next slide 2. How did they compare to extrafamilial child molesters? Next slide 3. How did they compare to controls?3 slides 1. Results did NOT support hypotheses- Biological fathers were least likely to be deviant Not surprisingly, fathers who molested children inside and outside the home were the most deviant Next slide 2. How did they compare to extrafamilial child molesters? Next slide 3. How did they compare to controls?

14. % with deviant preferences 3 slides 1. Results did NOT support hypotheses- Biological fathers were least deviant Not surprisingly, fathers who molested chidren inside and outside the home were the most deviant Next slide 2. How did they compare to extrafamilial child molesters? Next slide 3. How did they compare to controls?3 slides 1. Results did NOT support hypotheses- Biological fathers were least deviant Not surprisingly, fathers who molested chidren inside and outside the home were the most deviant Next slide 2. How did they compare to extrafamilial child molesters? Next slide 3. How did they compare to controls?

15. % with deviant preferences 3 slides 1. Results did NOT support hypotheses- Biological fathers were least deviant Not surprisingly, fathers who molested children inside and outside the home were the most deviant Next slide 2. How did they compare to extrafamilial child molesters? Next slide 3. How did they compare to controls?3 slides 1. Results did NOT support hypotheses- Biological fathers were least deviant Not surprisingly, fathers who molested children inside and outside the home were the most deviant Next slide 2. How did they compare to extrafamilial child molesters? Next slide 3. How did they compare to controls?

16. Rice & Harris (2002) 82 �incest� offenders: 52 molested their own biological daughters 30 molested stepdaughters or other non-genetically related �daughters� 37 of the above also had extrafamilial female victims 102 extrafamilial offenders vs. females

17. Characteristics of intra- and extra-familial child molesters Offender sexually abused as a child 35% Incest in offender�s family 17% Had drug or alcohol problems 33% -Offender sexually abused as a child is measured by self-report after the offender is apprehended -Mostly similar to findings in review paper by Williams & Finkelhor (1990) and their empirical study of 1995-Offender sexually abused as a child is measured by self-report after the offender is apprehended -Mostly similar to findings in review paper by Williams & Finkelhor (1990) and their empirical study of 1995

18. Father-daughter and other child molesters - In general, incest offenders lower risk on everything than nonincest - In general, genetic lower risk than other incest -In general, genetic & step lower risk than mixed- In general, incest offenders lower risk on everything than nonincest - In general, genetic lower risk than other incest -In general, genetic & step lower risk than mixed

19. Sexual Deviance Scores -Explain figure Note that ALL groups of offenders PREFERRED children- i.e. highest responses were to children - But both genetic and step fathers who had not also molested children outside the family were LESS deviant than those who had victims inside AND outside the family -Explain figure Note that ALL groups of offenders PREFERRED children- i.e. highest responses were to children - But both genetic and step fathers who had not also molested children outside the family were LESS deviant than those who had victims inside AND outside the family

20. Father-daughter and other child molesters - In general, incest offenders lower risk on everything than nonincest - In general, genetic lower risk than other incest -In general, genetic & step lower risk than mixed- In general, incest offenders lower risk on everything than nonincest - In general, genetic lower risk than other incest -In general, genetic & step lower risk than mixed

21. Mean VRAG and SORAG scores and rates of violent recidivism

22. VRAG/SORAG predicting recidivism (ROC areas)

23. Predicting Recidivism Among Father-Daughter Child Molesters Prediction instruments Violence Risk Appraisal Guide (VRAG) Sex Offender Risk Appraisal Guide (SORAG) Construction sample: AUC= .76 for violent Earlier sex offender sample: AUC= .77 for violent, .62 for sexual Independent contribution of �Intrafamilial Child Molester�

24. Four explanatory factors Sexual preferences and pedophilia Failure of incest avoidance Mate deprivation; opportunity Psychopathy, antisociality

25. Theoretical Implications Why do most men avoid incest? Our tentative hypothesis Nonspecific male incest avoidance -- general preference for adults as sex partners and general lack of psychopathy Only females have a specific incest avoidance mechanism Future research - Postpubertal victims So, why do men commit incest against their own offspring? -Common view has been that, contrary to other cases of child molesting, incest offenders are not motivated by an attraction to children (pedophilia). Instead, the popular assumption was that incest was a response to dysfunctional family dynamics -As we have seen, there is evidence of sexual deviance in incest offenders. And victims of biological exclusive fathers were youngest of all the groups (mean 8 yrs.) -But, are they more sexually deviant than men who molest their step-daughters? Doesn�t look like it. - So, neither the traditional psychoanalytic or cultural explanations seem to explain it, but neither does the propinquity-based explanation of Westermarck The incest-avoidance mechanism in fathers is their preference for adult females as mates. -Only females have a specific incest avoidance mechanism- Could be propinquity -Incest offenders are neither more sexually deviant nor more psychopathic than other nonfamilial offenders. But neither are they less so- Operative factor seems to be 1 vs. >1 victim -How we might test this- Look in incest offenders who molest their post-pubertal daughters-- Now we wouldn�t expect to find deviant sexual age preferences- Now would propinquity explain the results? Or psychopathy?So, why do men commit incest against their own offspring? -Common view has been that, contrary to other cases of child molesting, incest offenders are not motivated by an attraction to children (pedophilia). Instead, the popular assumption was that incest was a response to dysfunctional family dynamics -As we have seen, there is evidence of sexual deviance in incest offenders. And victims of biological exclusive fathers were youngest of all the groups (mean 8 yrs.) -But, are they more sexually deviant than men who molest their step-daughters? Doesn�t look like it. - So, neither the traditional psychoanalytic or cultural explanations seem to explain it, but neither does the propinquity-based explanation of Westermarck The incest-avoidance mechanism in fathers is their preference for adult females as mates. -Only females have a specific incest avoidance mechanism- Could be propinquity -Incest offenders are neither more sexually deviant nor more psychopathic than other nonfamilial offenders. But neither are they less so- Operative factor seems to be 1 vs. >1 victim -How we might test this- Look in incest offenders who molest their post-pubertal daughters-- Now we wouldn�t expect to find deviant sexual age preferences- Now would propinquity explain the results? Or psychopathy?

26. Practical Implications Similar to other child molesters: Importance of careful history Don�t assume no extrafamilial victims Importance of sexual deviance Importance of risk assessment Instruments developed for other offenders work just as well for incest offenders -Idea of having fathers look after daughters and be more involved in child-rearing? -Idea of having fathers look after daughters and be more involved in child-rearing?