Brian M. Bird

McMaster University | McMaster · Department of Psychiatry and Behavioural Neurosciences

Correlational research suggests that men show greater attraction to feminine female faces when their testosterone (T) levels are high. Men's preferences for feminine faces also seem to vary as a function of relationship context (short versus long-term). However, the relationship between T and preferences for female facial femininity has yet to be t...

A contribution to a special issue on Hormones and Human Competition. Since Archer's (2006) influential meta-analysis, there has been a major increase in the number of studies investigating the effect of competition outcome on testosterone reactivity patterns in humans. Despite this increased research output, there remains debate as to whether compe...

LAY SUMMARY This analysis of data from a large population-level survey uncovers a pressing issue related to mental health service use among Canadian Armed Forces members. Although many military members seek help for mental health issues, they often do not complete treatment. Data show that more than one-third of those who sought mental health care...

Past research has found that sexualized women are often dehumanized (i.e., attributed reduced human qualities).However, the mechanisms contributing to such dehumanization remain poorly understood. In this pre-registered experiment involving a within-subject, placebo-controlled, cross-over design, we tested whether testosterone contributes to men’s...

A behavioral economic reinforcer pathology model theorizes that alcohol problems are influenced by steep delay discounting, overvaluation of alcohol reinforcement, and low reinforcement from alcohol-free activities. Extending this account to the comorbidity of alcohol problems and posttraumatic stress disorder (PTSD), the present study tested the h...

The mating effort questionnaire (MEQ) is a multi-dimensional self-report instrument that captures factors reflecting individual effort in upgrading from a current partner, investment in a current partner, and mate seeking when not romantically paired. In the current studies, we sought to revise the MEQ so that it distinguishes among two facets of m...

Background and Aims Behavioral economic theory predicts that high alcohol demand and high proportionate alcohol‐related reinforcement are important determinants of risky alcohol use in emerging adults, but the majority of research to date has been cross‐sectional in nature. The present study investigated prospective and dynamic relationships betwee...

Objective Canadian Armed Forces (CAF) members and Veterans are more likely to experience mental health (MH) conditions, such as posttraumatic stress disorder (PTSD), than the general Canadian population. Previous research suggests that an increasing number of individuals are employing cannabis for MH symptom relief, despite a lack of robust evidenc...

Delay discounting-the extent to which individuals show a preference for smaller immediate rewards over larger delayed rewards-has been proposed as a transdiagnostic neurocognitive process across mental health conditions, but its examination in relation to posttraumatic stress disorder (PTSD) is comparatively recent. To assess the aggregated evidenc...

Exclusion from social relationships is a painful experience that may threaten an individual’s status and dominance. The steroid hormone testosterone, which fluctuates rapidly in response to such threats, may be implicated in subsequent behavioral action (e.g., aggressive or prosocial responses) that aims to protect or enhance one’s status after exc...

The Intrasexual Competition Scale measures the extent to which individuals view their interaction with same-sex others in competitive terms. Although it is frequently used in studies investigating differences in mating behavior, the factor structure of the Intrasexual Competition Scale has never been confirmed. Researchers have yet to use multiple-...

Background Differences in healthcare delivery systems and pathways to mental healthcare for Canadian Armed Forces (CAF) members and Veterans may contribute to variations in mental health services use (MHSU) and the factors associated with it. We: (1) estimated the prevalence of past 12-month MHSU (≥1 visit with a medical or mental health profession...

Psychological research has produced a rich body of empirical data documenting humanity’s propensity to commit infidelity in the context of long-term relationships, but comparatively little work has been dedicated to synthesizing these data into an integrated framework that encompasses the full range of its processes, from why it occurs in the first...

Life-history theory provides a framework for understanding the resource trade-offs that are inherent in the struggle to maximize reproductive fitness. Hormones, and testosterone in particular, play important roles in mediating some of the morphological, behavioral, and physiological traits that are implicated in these trade-offs—one of the most wid...

Attractiveness judgements influence desires to initiate and maintain romantic relationships. Testosterone also predicts relationship initiation and maintenance; such effects may be driven by the hormone's modulation of attractiveness judgements, but no studies have investigated causal (and situation-dependent) effects of the hormone on these judgem...

Despite global efforts to rapidly distribute COVID-19 vaccines, early estimates suggested that 29–35% of the population were hesitant/unwilling to receive them. Countering such vaccine hesitancy is thus an important priority. Across two sets of online studies (total n = 1584) conducted in the UK before (August–October 2020) and immediately after th...

Competition is a defining feature of most living organisms. Among humans, the engagement in, and the associated outcomes of, competition (i.e., win or loss) can hold important consequences for survival, individual and group status, and mating-related opportunities. As such, considerable research efforts have been devoted to identifying and delineat...

This handbook is currently in development, with individual articles publishing online in advance of print publication. At this time, we cannot add information about unpublished articles in this handbook, however the table of contents will continue to grow as additional articles pass through the review process and are added to the site. Please note...

A resurgence of research has begun to systematically examine the relationship between psychedelic use and mental health and well-being. Although preliminary findings examining the therapeutic value of these substances show promise, the mechanisms through which psychedelic use may predict reduced mental distress remain poorly understood. To this end...

Toma un Asiento: Perspectivas de Supervisados en el Uso de Juego de Roles Basados en Silla durante la Supervisión Clínica Las investigaciones indican que la supervisión tiene un papel crítico en el entrenamiento de los psicólogos clínicos. Sin embargo, existen brechas importantes en nuestro entendimiento de como las técnicas supervisoras particular...

Testosterone is often considered a critical regulator of aggressive behaviour. There is castration/replacement evidence that testosterone indeed drives aggression in some species, but causal evidence in humans is generally lacking and/or-for the few studies that have pharmacologically manipulated testosterone concentrations-inconsistent. More often...

Like other animals, humans are sensitive to facial cues of threat. Recent evidence suggests that we use this information to dynamically calibrate competitive decision-making over resources, ceding more to high-threat individuals (who appear more willing/able to retaliate) and keeping more from low-threat individuals. Little is known, however, about...

The Challenge Hypothesis (Wingfield et al., 1990) originally focused on adult male avian testosterone elevated in response to same-sex competition in reproductive contexts. The purpose of the present paper is to demonstrate how the Challenge Hypothesis has shaped ideas about human life histories. We conduct a citation analysis, drawing upon 400 Goo...

Theoretical models, such as the minority stress model, suggest that sexual and gender minority (SGM) youth may be overrepresented in the justice system. However, few studies have examined rates of SGM youth in the system, and even fewer have compared them with rates of these youth in the broader community. To obtain a more accurate estimate, we con...

Little is known about the neurobiological pathways through which testosterone promotes aggression or about the people in whom this effect is observed. Using a psychopharmacogenetic approach, we found that testosterone increases aggression in men ( N = 308) with select personality profiles and that these effects are further enhanced among those with...

Topic The Brief Services psychotherapy paradigm has evolved to produce cost‐effective and clinically significant outcomes in children’s mental health. Though its clinical evaluation is still in its infancy, it has been utilized to a much lesser degree with autism spectrum disorders, which typically require a longer‐term approach to psychotherapy tr...

The social heuristic hypothesis posits that human cooperation is an intuitive response that is expressed especially under conditions of time-constraint. Conversely, it proposes that for individuals given an opportunity for reflection, cooperation is more likely to be curtailed by an optimizing process calibrated to maximize individual benefit in a...

Previous research has linked the facial width-to-height ratio (FWHR) to a host of psychological and behavioral characteristics, primarily in men. In two studies, we examined novel links between FWHR and sex drive. In Study 1, a sample of 145 undergraduate students revealed that FWHR positively predicted sex drive. There were no significant FWHR × s...

Background: Recent evidence suggests that psychedelic use predicts reduced perpetration of intimate partner violence among men involved in the criminal justice system. However, the extent to which this association generalizes to community samples has not been examined, and potential mechanisms underlying this association have not been directly exp...

The zeitgeist for brief services psychotherapy efficacy is well underway within the individual and family therapy treatment modalities. However, this paradigm shift, to produce clinically significant mental health outcomes in a much shorter time, has evolved to a much lesser degree within the treatment group format. Longer-term treatment group prot...

Previous research indicates that men’s testosterone levels, or personality and contextual variables known to influence testosterone levels, predict men’s attributions of social and personality characteristics from faces. However, the correlational nature of many of these past findings precludes our ability to establish causal pathways. Here, across...

Although effective treatments exist for transitional-aged youth presenting with dysphoria, treatment protocols are often much longer than the typical length of psychotherapy that clients receive. The current authors proposed a three-session treatment protocol with an emphasis on the process of externalizing and shifting problem-focused identities u...

One of the most widely studied biological correlates of aggressive behavior is the steroid hormone testosterone. Although traditional wisdom might suggest that individuals with more testosterone are more likely to be aggressive, research over the past several decades has identified important contextual, individual difference, and methodological var...

Rapid testosterone fluctuations in response to social stimuli are observed across a wide range of species, and the highly conserved nature of these fluctuations suggests an adaptive function. This paper reviews the current literature on testosterone reactivity, primarily in human males, and illustrates how life-history theory provides an adequate t...

Introduction: Geography is a determinant of health. For persons residing in northern and rural regions in Ontario, evidence shows that they are more likely to be retained in opioid agonist therapy compared to their southern counterparts. The contextual factors associated with this observation, however, are not well known. Polysubstance use is a fac...

Envy has recently been considered from an evolutionary perspective as an emotion which might motivate compensatory action following unfavorable social comparisons. In two studies, the role of envy in women’s motivation to enhance their physical appearance was examined. Study 1 explored the mediating role of dispositional envy on the relationship be...

Background: Although traditional wisdom suggests that baseline levels of testosterone (T) promote aggressive behavior, decades of research have produced findings that have been largely weak and inconsistent. However, more recent experimental work suggests that exogenous administration of T rapidly potentiates amygdala and hypothalamus responses to...

Correlational research has linked low mate value (MV)—one’s worth as a mating partner to members of the opposite sex—with aggression in men. In 2 experiments, we examined the effects of self-perceived MV on men’s reported willingness to aggress directly toward a hypothetical mate poacher (Experiment 1, N = 60) and observable aggression toward a sam...

The study compares voluntary and involuntary groups of patients, and provides the first detailed description of involuntary admissions to a Canadian child and adolescent inpatient psychiatry setting. The involuntary group was found to have a higher percentage of adolescents, patients with suicide risk, patients living away from families, and patien...

Variation in the facial width-to-height ratio (fWHR) maps onto a number of behavioral and psychological traits among men (e.g., aggression, unethical behavior, negotiation performance). Importantly, observer judgments of many of these traits also correlate strongly with the fWHR, suggesting that it may represent an honest cue to dominance and statu...

Over evolutionary history, sexual attractiveness has had a large influence on the propagation of an organism’s genes in sexually-reproducing species such as humans: individuals most desirable to members of the opposite sex were more likely to attract and retain a mate. In this chapter, we discuss the importance of attractiveness to two facets of se...