Martin Daly's research while affiliated with McMaster University and other places

Publications (140)

Article
Full-text available
Darwin’s theory of sexual selection provides a useful framework for understanding the behavior of stepparents. A non-human animal whose new mate has dependent young may kill, ignore, or adopt the predecessor’s progeny. The third option has been interpreted as courtship (“mating effort”), and whether selection favors such investment over killing or...
Article
Full-text available
In-laws (relatives by marriage) are true kin because the descendants that they have in common make them “vehicles” of one another’s inclusive fitness. From this shared interest flows cooperation and mutual valuation: the good side of in-law relationships. But there is also a bad side. Recent theoretical models err when they equate the inclusive fit...
Article
Full-text available
Grandparents are important childcare providers, but grandparental relationship status matters. According to several studies, caregiving is reduced after grandparental divorce, but differential responses by grandmothers versus grandfathers have often been glossed over. To explore the effects of relationship status on grandparental care, we analysed...
Article
Survey data from 36,771 European grandparents were analyzed with respect to childcare assistance that interviewees provided to their birth children versus stepchildren. Interviewees with current partners provided far more such assistance to adult children who were the progeny of both partners than to those who were stepchildren of either one's self...
Article
Grandmothers provide more childcare for their daughters' children than for those of their sons, almost everywhere. Exceptions occur where virilocal (patrilocal) postmarital residence makes the children of sons more accessible, but even under virilocality, preferential care of daughters' children, net of the effects of proximity, is often demonstrab...
Article
Pepper & Nettle's (P&N's) argument is compelling, but apparently contradictory data are easily found. Associations between socioeconomic status (SES) and substance abuse are sometimes positive, the poor are sometimes eager to educate their children, and perceptions of local mortality risk can be so distorted as to constitute an implausible basis fo...
Poster
Full-text available
Objetivos: Investigar o efeito da exposição à violência (EV) sobre os comportamentos de risco à saúde de adolescentes das 26 capitais brasileiras e do Distrito Federal e analisar a associação entre a magnitude deste efeito e fatores contextuais no nível da cidade. Métodos: Estudo transversal com base nos dados da Pesquisa Nacional de Saúde do Escol...
Article
Full-text available
Children receive more care and resources from their maternal grandmothers than from their paternal grandmothers. This asymmetry is the " matrilateral bias " in grandmaternal investment. Here, we synopsize the evolutionary theories that predict such a bias, and review evidence of its cross-cultural generality and magnitude. Evolutionists have long m...
Article
Full-text available
Maternal grandmothers invest more in childcare than paternal grandmothers. This bias is large where the expression of preferences is unconstrained by residential and lineage norms, and is detectable even where marriage removes women from their natal families. We maintain that the standard evolutionary explanation, paternity uncertainty, is incomple...
Article
Full-text available
This study assessed the consistency of self-reports of risk behavior (overall and within four specific domains: alcohol use, tobacco use, drug use, and sexual activity) in two editions of the Brazilian National School Based Survey of Adolescent Health (PeNSE): 2009 and 2012. The overall proportion of cases with at least one inconsistent response in...
Article
Van Lange et al. propose that climate affects violence via its effects on life history. That much is reasonable (and not novel), but their theory lacks causal specificity. Their foundational claim of an association between heat and violence is not well documented, and several findings that the authors themselves cite seem inconsistent with their mo...
Article
This study integrates insights from evolutionary psychology and social epidemiology to present a novel approach to contextual effects on health-risk behaviors (unprotected sex, drunkenness episodes, drugs and tobacco experimentation) among adolescents. Using data from the 2012 Brazilian National Survey of Adolescent Health (PeNSE), we first analyze...
Article
Full-text available
The use of kinship families to provide foster care has been increasing due to changes in legislation and the hope that it will provide better quality placements, but there has been little consideration of differential outcomes based on sub-types of kin. Using data from one Ontario, Canada, child protection agency we compared the frequency and stabi...
Article
Jerry Hogan has forcefully maintained that cause and function are distinct questions, and that attempts to integrate them are conceptually muddled. I dissent from his view, maintaining that causal analysis is conducted in the shadow of premises about function, and that bringing functional ideas out of the shadows facilitates the generation of fruit...
Article
We compared Future Discounting (FD, preference for smaller, sooner rewards over larger, later ones) by 160 Brazilian youth (1630years old; 71 women and 89 men). University students and slum-dwelling (favela) youth were compared. Participants completed a monetary FD task, a scale of youngsters view of their neighborhood, and self-reported exposure t...
Article
Margo Wilson and collaborators discovered that cohabiting couples had very much higher spousal homicide rates than those in registered marriages, and cross-national research has shown this difference to be widespread. We now find that homicide rates in the two sorts of unions have converged in the United States, such that the previously large diffe...
Article
We compared the stability of kinship and non-kin foster placements in the cases handled by one Ontario (Canada) child protection agency in 2008–2010. Non-kin placements were four times more likely than kin placements to end within the first month; this difference then decreased, but kin placements remained significantly more stable in months 2 th...
Article
Martin Daly explores Steven Pinker's treatise on the taming of human aggression.
Article
Full-text available
A major trend in foster care in developed countries over the past quarter century has been a shift toward placing children with "kin" rather than with unrelated foster parents. This change in practice is widely backed by legislation and is routinely justified as being in the best interests of the child. It is tempting to interpret this change as in...
Article
Paternity is uncertain, so if paternal feelings evolved to promote fitness, we might expect them to vary in response to variables indicative of paternity probability. We therefore hypothesized that the risk of lapses of paternal affection, including abusive assaults on children, will be exacerbated by cues of non-paternity. Cross-sectional study of...
Article
Full-text available
In a 12-year study involving 191 radio-tracked Merriam's kangaroo rats and 337 subcutaneous radio implantations, females were killed by predators at a rate of 0.0054 per radio-bearing night and males at a rate of 0.0116. Both the mortality rate and the sex difference therein declined over the course of several nights after radio implantation. Femal...
Article
Full-text available
To assess a new impunity index and variables that have been found to predict variation in homicide rates in other geographical levels as predictive of state-level homicide rates in Brazil. This was a cross-sectional ecological study. Data from the mortality information system relating to the 27 Brazilian states for the years 1996 to 2005 were analy...
Article
Full-text available
An evolutionary psychological perspective drawing on sexual selection theory can better explain sex differences in aggression and violence than can social constructionist theories. Moreover, there is accumulating evidence that, in accordance with predictions derived from sexual selection theory, men modulate their willingness to engage in risky and...
Article
Psychology, neuroscience and physiology are missing from a new sociological study of violence.
Article
Full-text available
Intimate partner violence against women is prevalent and is associated with poor health outcomes. Understanding indicators of exposure to intimate partner violence can assist health care professionals to identify and respond to abused women. This study was undertaken to determine the strength of association between selected evidence-based risk indi...
Article
Previous research has shown that viewing photos of highly attractive women adversely affects men's evaluations of more typical women and of their own romantic partners. We could not replicate these results, but induced similar effects by showing participants an innocuous mock video interview of an opposite-sex stranger. Mated men's ratings of their...
Article
It has been the prevailing view that young offenders are more present oriented than their peers, but this view has little empirical basis other than the actions that have defined these youth as offenders. In the present study, we used a decision task with actual monetary consequences to assess the tendency of young offenders and a control group of...
Article
Full-text available
Henrich et al.'s nice cross-cultural experiments would benefit from models that specify the decision rules that humans use and the specific developmental pathways that allow cooperative norms to be internalized. Such models could help researchers to design further experiments to examine human social adaptations. We must also test whether the “same”...
Article
People readily make attributions about the likely behavior of others, based on very limited information. We exploited this tendency to assess people's sensitivity to personological and social-circumstantial evidence of risk of coercive control in romantic relationships, by unobtrusively varying information about a fictitious couple in a between-gro...
Article
Organisms typically "discount the future" in their decision making, but the extent to which they do so varies across species, sexes, age classes, and circumstances. This variability has been studied by biologists, economists, psychologists, and criminologists. We argue that the conceptual framework required for an interdisciplinary synthesis of kno...
Article
Schmitt finds that national sex ratios predict levels of sociosexuality, but how we should interpret this result is unclear for both methodological and conceptual reasons. We criticize aspects of Schmitt's theorizing and his analytic strategy, and suggest that some additional analyses of the data in hand might be illuminating.
Article
Organisms 'discount the future' when they value imminent goods over future goods. Optimal discounting varies: selection should favour allocations of effort that effectively discount the future relatively steeply in response to cues promising relatively good returns on present efforts. However, research on human discounting has hitherto focused on s...
Article
One reason why humans don't behave according to standard game theoretical rationality is because it's not realistic to assume that everyone else is behaving rationally. An individual is expected to have psychological mechanisms that function to maximize his/her long-term payoffs in a world of potentially “irrational” individuals. Psychological deci...
Chapter
This chapter discusses the variations in homicide as indicative of variations in competitive risk taking, interpreting prevalent conflict typologies and demographic patterns as reflections of evolved motivational and information processing mechanisms that function to regulate competitive inclinations and actions. Connections are then drawn to resea...
Chapter
In der wissenschaftlichen Beschäftigung mit gewalttätigen Handlungen von Menschen versucht der evolutionspsychologische Ansatz, ein Modell zu entwickeln, das Vorhersagen darüber ermöglicht, welche Personen unter welchen Umständen zur Gewalttätigkeit neigen werden und gegen wen sich die Gewalt wahrscheinlich richten wird. Dies geschieht im Rahmen ei...
Article
Stepparents commit child abuse and homicide at much higher rates than genetic parents. Proposed exceptions, including a recent claim that there is no such "Cinderella effect" in Swedish homicides, are shown to be mistaken. The hypothesis that only "mothers' boyfriends" abuse children excessively, whereas married stepfathers do not, is tested and re...
Article
Previous research showing that income inequality (assessed by the Gini index) is a predictor, and hence a possible determinant, of homicide rates, whether at the cross-national, state, or city level, has been inconclusive because of a negative relationship between economic inequity and average income. Comparison across the Canadian provinces provid...
Article
Full-text available
Human males are more polygamously inclined than females. However, there is substantial within-sex variation in polygamous inclinations and practices. This is acknowledged by Gangestad & Simpson but we pose the question: Is the target article's “strategic pluralism” pluralistic enough? In addition, we argue that the hypothesis that the female orgasm...
Article
Comments on the L. B. Silverstein and C. F. Auerbach (see record 1999-05337-001) examination of the essentialist perspective on fathering, family structure, and child development. It is stated that Silverstein and Auerbach misrepresented what is known about rates of child abuse at the hands of stepparents vs genetic parents. (PsycINFO Database Reco...
Chapter
Kangaroo rats (Dipodomys, Heteromyidae) are nocturnal, facultatively bipedal, burrow-dwelling rodents, inhabiting arid and grassy habitats in western North America (Genoways and Brown 1993). The family Heteromyidae consists of six genera, of which pocket mice (Chaetodipus and Perognathus) and kangaroo mice (Microdipodops) are sympatric with kangaro...
Article
There was significant (P<.01) nonrandom spatial-temporal clustering (on a scale from 0 to 5 km and 0 to 30 days) of those homicide incidents in Chicago, Illinois, (1965-1990) in which men killed unrelated men in the context of gang activities and other social conflicts, but not in robbery-burglary homicide incidents. The GIS spatial point patternin...
Article
Homo sapiens is increasingly being studied within the evolutionary (adaptationist, selectionist) framework favoured by animal behaviour researchers. There are various labels for such work, including evolutionary psychology, human behavioural ecology and human sociobiology. Collectively, we call these areas 'human evolutionary psychology' (HEP) beca...
Article
There is a cross-culturally universal sex difference in homicide perpetration, and motives of male sexual proprietariness and rivalry are implicated in some substantial proportion of all homicides everywhere. With the exception of some forensic psychiatrists, however, criminologists have paid these motives little explicit attention. Human motives a...
Article
In comparisons among Chicago neighbourhoods, homicide rates in 1988-93 varied more than 100-fold, while male life expectancy at birth ranged from 54 to 77 years, even with effects of homicide mortality removed. This "cause deleted" life expectancy was highly correlated with homicide rates; a measure of economic inequality added significant addition...
Article
Mainstream social psychology has sought parsimonious explanations of broad general applicability, and has in practice focused on stranger interactions. An evolutionary perspective; however, justifies predicting a rich diversity of relationship-specific social psychological adaptations. The demands of motherhood, fatherhood, mateship, sibship and ot...
Article
Information about uxoricides (killings of wives) in one Canadian city between 1974 and 1995 was extracted from media reports. Among those slain women who were mothers of coresident minor children, half had children sired by former partners, compared to just 7% of comparable such mothers in the population at large, yielding an odds ratio of 12.7. Th...
Article
Criminological theories are usually framed in sociological terms but always entail psychological assumptions. Psychological accounts, in their turn, entail assumptions about the adaptive "design" of evolved mental mechanisms and processes. Thus, explicit attention to recent theory and research on psychology and evolution can sometimes help criminol...
Chapter
Homicide is gendered: The circumstances in which men and women kill and are killed tend to be quite different, as are the demographic patterns of risk and the apparent motivating factors. Whereas most male-victim homicides occur in the context of competitive conflicts among men, women almost never kill women in similar contexts (Daly and Wilson, 19...
Article
Sexual selection theory affords a rationale for predicting that men, especially young men, may be more willing than women to risk harms and to discount the future in the pursuit of short-term gains. These propositions apply to many domains of risky behavior, and it is likely that they apply to decisions involving potential harms to the environment...
Article
There is a cross-culturally ubiq- I uitous connection between men's sexual possessiveness and men's violence.1 We have studied ac counts of uxoricides (wife killings) from a broad range of societies, and find that male sexual propri etariness?broadly construed to encompass resentment both of in fidelity and of women's efforts to leave marriages?is...
Article
Although in a sense "genetic', the conceptual framework of evolutionary psychology, behavioural ecology and sociobiology is distinct from that of behaviour genetics. Considerable confusion has resulted from failures to recognize the distinctions. These disciplines are primarily concerned with the characterization of evolved adaptations, which are u...
Article
Two Statistics Canada data sources provide case information on violence against Canadian wives : the "Homicide Survey", an archive of all homicides known to police since 1974, and the 1993 national telephone "Violence against Women Survey". When combined with population-at-large information, these sources illuminate risk patterns for lethal and non...
Article
Photographs of a freshwater harbour and contiguous wetlands were electronically scanned and then altered, to study effects of visual cues of water quality on various judgments. Subjects viewed the images on a computer monitor and indicated their ratings by clicking a ‘mouse’. Effects were assessed by between-group comparisons of responses to pictur...
Article
A familicide is a multiple-victim homicide incident in which the killer's spouse and one or more children are slain. National archives of Canadian and British homicides, con- taining 109 familicide incidents, permit some elucidation of the characteristic and epi- demiology of " crime. Familicides were almost exclusively perpetrated by men, unlike o...
Article
Killings of children less than five years of age by stepfathers versus (putative) genetic fathers are compared on the basis of Canadian and British national archives of homicides. In addition to previously reported differences in gross rates, the two categories of killings differed in their attributes. Beatings constituted a relatively large propor...
Article
This paper examines patterns in spousal homicide in Canada between 1974 and 1992. Among the findings highlighted in this paper are: spousal homicide rates have remained stable with an average of 17 victims per million couples per annum over the period 1974-92; there is a substantial variation in provincial spousal homicide rates, with the lowest ra...
Article
PIP This article assesses the possible association between stepfatherhood and violence against wives in Hamilton, Ontario. The sample population comprised women who sought refuge from abusive male partners at a shelter for abused women and their children during 1986-87. Comparing shelter data for 1986-87 with survey data for 1983, results showed th...
Article
A particularly nasty husband might hit his wife with the sharp edge of a machete or axe or shoot a barbed arrow into some nonvital area, such as the buttocks or the leg. Another brutal punishment is to hold the glowing end of a piece of firewood against the wife's body, producing painful and serious burns. Normally, however, the husband's reprimand...
Article
Frequencies of homicide victimization of wives and husbands, while cohabiting and when separated, are reported for all spousal homicides known to the police in Canada (1974-1990), in New South Wales, Australia (1968-1986), and in Chicago (1965-1990). In all three data sets, the degree to which spousal homicide victimization was female-biased was si...
Article
The temporal and spatial distribution of above-ground activith in Merriam's kangaroo rats, Dipodomys merriami, radio-tracked during 10 winters varied in relation to phases of the moon. At the full moon, animals were more likely to be found in their day burrows at scheduled hourly radio fixes, and when they emerged, they stayed closer to home. At pa...
Article
Full-text available
We observed radio-implanted Merriam's kangaroo rats disposing of 10-g bonanzas of rolled oats in 48 trials in the field. The principal determinant of the initial disposition of discovered food was apparently its distance from the day burrow: food found within about 10m was mainly larder hoarded, whereas food encountered farther afield was usually d...
Article
A hitherto unremarked peculiarity of homicide in the United States is that women kill their husbands almost as often as the reverse. For every 100 US. men who kill their wives, about 75 women kill their husbands; this spousal “sex ratio of killing” (SROK) is more than twice that in other Western nations. Our analyses of spousal homicide samples fro...

Citations

... Grandfathers, are substantially less likely to provide grandchild care in any relationship status other than continued marriage to the grandmother. [20] A more detailed longitudinal analysis on the dynamics of health outcomes of grandchild care is needed, considering that grandchild care is closely related to family arrangement and female labor force participation. [19] Finally, caring for grandchildren can help increase or maintain physical activity among grandparents, which is associated with improved wellbeing and physical health, as well as reducing symptoms of anxiety and depression. ...
... First, all women benefit reproductively from staying alive long enough to invest in both children (especially daughters) and grandchildren (Daly & Perry, 2021;. Second, men's fighting power , fluid cognitive abilities (Salthouse, 1996), and fertility decline with age (Matsumoto, 2002;Santiago, Silva, Alves, Oliveira, & Fardilha, 2019), thereby reducing many elements that contribute to male mating success. ...
... In the process of harming others, the aggressor themselves may also be injured and, with the possible exception of self-defense, often incurs third-party punishment (e.g., moral condemnation, incarceration). However, aggressive behaviors are observed in virtually all known human societies (Buss & Shackelford, 1997;Daly & Wilson, 1988) and many other animals (Archer, 1988;Huntingford & Turner, 1987). This is likely because aggressive behaviors can increase the aggressor's reproductive success by excluding others from accessing scarce, fitnessenhancing resources (e.g., food, shelter, mates; Archer, 1988;Huntingford & Turner, 1987). ...
... La subordinación no solo ha hecho que la violencia sea socialmente aceptada sino que se ha incrustado en las instituciones sociales, al mismo tiempo que estas la han reproducido (Taylor & Jasinski, 2011). Para que ello surja efecto, el cuerpo de la mujer debe objetivizarse y convertirse en propiedad sexual y reproductiva de los hombres, quienes pueden poseerlo e intercambiarlo (Wilson & Daly, 1992). De ahí que, según las autoras, en muchos estudios el feminicidio tenga como historia de base a características similares como celos, sentido de propiedad, respuesta violenta a infidelidad o fin de la relación. ...
... 8. See note 3. 9. Daly and Wilson's (1999) use of this label for ''the entire field'' (or to be more precise, for both adaptive behavior and behavioral mechanisms) actually led to debate (see Smith et al., 2000 and reply from Daly and Wilson, 2000). It should be pointed out that some researchers, like Daly and Wilson, think the split between focusing on adaptive behavior versus behavioral mechanisms is artificial (Martin Daly, personal correspondence, 2001). ...
... in Germany yet found the opposite with the greater investment among paternal grandparents in rural Greece, though a later related survey found that this difference for rural Greece was not reproducible (Daly & Perry, 2019;Pashos, 2000). Another rural culture in the State of Iowa, U.S., was found to have somewhat equivalent measures for comparing maternal and paternal grandparents. ...