Peter L Hurd

Peter L Hurd
University of Alberta | UAlberta · Neuroscience and Mental Health Institute

BSc (Hons), MSc, PhD.

About

101
Publications
21,102
Reads
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3,408
Citations
Introduction
Sex and Violence Lab research directions: Influence of early development, and sexual differentiation, on adult personality, especially aggressiveness; Genetics and epigenetics of individual differences in behaviour.
Additional affiliations
May 2001 - present
University of Alberta
December 1998 - May 2001
January 1994 - December 1997
Stockholm University
Position
  • PhD Student
Education
September 1990 - May 1993
Simon Fraser University
Field of study
  • Behavioural Ecology
September 1985 - May 1990
Carleton University
Field of study
  • Biology & Psychology (Neuroscience)

Publications

Publications (101)
Article
Full-text available
Studying environmental sex determination (ESD) in cichlids provides a phylogenetic and comparative approach to understand the evolution of the underlying mechanisms, their impact on the evolution of the overlying systems, and the neuroethology of life history strategies. Natural selection normally favors parents who invest equally in the developmen...
Article
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Mutations affecting the synaptic-scaffold gene SHANK3 represent the most common genetic causes of autism with intellectual disability, accounting for about 1-2% of cases. Rare variants of this gene have also been associated with schizophrenia, and its deletion results in the autistic condition known as Phelan–McDermid syndrome. Despite the importan...
Article
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How is cognitive empathy related to sociality, imagination, and other psychological constructs? How is it altered in disorders of human social cognition? We leveraged a large data set (1,168 students, 62% female) on the Reading the Mind in the Eyes test (RMET), the Autism Quotient (AQ), and the Schizotypal Personality Questionnaire (SPQ-BR) to test...
Article
A fit animal must develop testes or ovaries, with brain and physiology to match. In species with alternative male morphs this coordination of development across tissues operates within sexes as well as between. For Pelvicachromis pulcher, an African cichlid in which early pH exposure influences both sex and alternative male morph, we sequence both...
Article
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Early life experience may have lifelong influences on an individual's behaviour in ways that are either adaptive or maladaptive depending in part on whether these early experiences accurately foreshadowed conditions in later life. Stress coping style is one example of a suite of behaviours, or personality traits, that may be influenced by early exp...
Article
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The paternally expressed gene SNORD116 encodes a set of short nucleolar RNAs that affect the expression of hundreds of other genes via epigenetic interactions. Lack of expression for SNORD116 has been implicated in major phenotypes of Prader-Willi Syndrome (PWS). Rates of psychosis and autism spectrum disorders are greatly increased in PWS, but the...
Article
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The extreme male brain theory of autism posits that its male bias is mediated by exaggeration of male-biased sex differences in the expression of autism-associated traits found in typical populations. The theory is supported by extensive phenotypic evidence, but no genes have yet been described with properties that fit its predictions. The autophag...
Article
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The elevated plus maze is a commonly used and well-validated test of anxiety-related behaviour in rodents. The use of fish in behavioural neuroscience paradigms is increasing, necessitating an equivalent test for studying anxiety-like behaviour in fish. Because behaviour in the elevated plus maze is driven by aversion to open space, the submerged p...
Article
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The relationships of spirituality with human social cognition, as exemplified in autism spectrum and schizophrenia spectrum cognitive variation, remain largely unstudied. We quantified non-clinical levels of autism spectrum and schizotypal spectrum traits (using the Autism Quotient and the Schizotypal Personality Questionnaire-Brief Revised) and di...
Article
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The maternally expressed imprinted gene UBE3A has been implicated in autism, schizophrenia and psychosis. The phenotype of Angelman syndrome, caused by loss of UBE3A expression, involves autism spectrum traits, while Prader-Willi syndrome, where the genotype of maternal disomy increases dosage of UBE3A, shows high penetrance for the development of...
Preprint
Full-text available
The paternally imprinted gene UBE3A has been implicated in autism, schizophrenia and psychosis. The phenotype of Angelman syndrome, caused by loss of UBE3A expression, involves autism spectrum traits, while Prader-Willi syndrome, where the genotype of maternal disomy increases dosage of UBE3A, shows high penetrance for the development of psychosis....
Article
The elevated plus maze is a prominent and well-documented test for studying anxiety in rodents. Fish are becoming more prevalent in studies of anxiety, yet the elevated plus maze has not been adapted and validated for fish. In the present study, we created an aquatic version of the elevated plus maze called the 'submerged plus maze,’ which is shape...
Article
Common alleles associated with psychiatric disorders are often regarded as deleterious genes that influence vulnerability to disease, but they may also be considered as mediators of variation in adaptively structured cognitive phenotypes among healthy individuals. The schizophrenia-associated gene GRIN2A (glutamate ionotropic receptor NMDA type sub...
Article
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This study was aimed at mapping the organization of the projections from the inferior olive (IO) to the ventral uvula in pigeons. The uvula is part of the vestibulocerebellum (VbC), which is involved in the processing of optic flow resulting from self-motion. As in other areas of the cerebellum, the uvula is organized into sagittal zones, which is...
Article
The psychological effects of brain-expressed imprinted genes in humans are virtually unknown. Prader-Willi syndrome (PWS) is a neurogenetic condition mediated by genomic imprinting, which involves high rates of psychosis characterized by hallucinations and paranoia, as well as autism. Altered expression of two brain-expressed imprinted genes, MAGEL...
Article
The gene SETDB2, which mediates aspects of laterality in animal model systems, has recently been linked with human handedness as measured continuously on a scale from strong left to strong right. By contrast, it was marginally associated with a left-right dichotomous measure, and it showed no evidence of association with absolute handedness strengt...
Article
We genotyped a healthy population for three haplotype-tagging FOXP2 SNPs, and tested for associations of these SNPs with strength of handedness and questionnaire-based metrics of inner speech characteristics (ISP) and speech fluency (FLU), as derived from the Schizotypal Personality Questionnaire-BR. Levels of mixed-handedness were positively corre...
Article
Zebrin II (ZII; a.k.a. aldolase C) is expressed heterogeneously in Purkinje cells (PCs) such that there are sagittal stripes of high expression (ZII+) interdigitated with stripes of little or no expression (ZII-). The pigeon flocculus receives visual-optokinetic information and is important for generating compensatory eye movements. It consists of...
Article
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Cerebral lateralization, the partitioning of functions into a certain hemisphere of the brain, is ubiquitous among vertebrates. Evidence suggests that the cognitive processing of a stimulus is performed with a specific hemisphere depending in part upon the emotional valence of the stimulus (i.e. whether it is appetitive or aversive). Recent work ha...
Article
Adult sex ratios in the kribensis cichlid (Pelvicachromis pulcher) are influenced by environmental conditions during early development. These environmental sex-determining factors may also organize life-long variation in social behavior within each sex. If this is true, then individual differences in behavior may be, at least in part, expressions o...
Article
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Social living has evolved numerous times across a diverse array of animal taxa. An open question is how the transition to a social lifestyle has shaped, and been shaped by, the underlying neurohormonal machinery of social behaviour. The nonapeptide neurohormones, implicated in the regulation of social behaviours, are prime candidates for the neuroe...
Article
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Variation in the arginine vasopressin receptor 1a (AVPR1a) gene is associated with autism risk in clinical populations and with variation in social behaviour in non-clinical populations. However, whether a relationship exists between AVPR1a polymorphisms and non-clinical manifestations of autism spectrum phenotypes has not been established. In this...
Article
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The formation of long-term memories for food sources is essential for the survival of most animals. Long-term memory formation in mammalian species has been demonstrated through a variety of conditioning tasks, however, the nature of long-term memory in fish is less known. In the current study, we explored whether African cichlids (Labidochromis ca...
Article
Common polymorphisms in the gene PCSK6, whose protein product mediates the development of brain and body asymmetry through the NODAL pathway, have recently been associated with handedness in three studies, making it a key candidate gene for understanding the developmental and expression of human lateralization. We tested the hypothesis that the PCS...
Article
How an organism deals with stressors is an integral component of survival. Recent research has shown that differences in a well-studied personality axis in fish, the shy-bold axis, relate to stress-coping behaviours. Bold fish tend to cope in a proactive manner (e.g. fighting) while shy fish cope more reactively (e.g. freezing). Because bold fish b...
Article
The hormones oxytocin and testosterone have been implicated in autism spectrum and schizophrenia-spectrum cognition and disorders, but their roles in mediating these psychological phenotypes remain largely unknown. We genotyped a large set of healthy individuals for loci that represent established genetic indicators of serum testosterone and oxytoc...
Article
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Background Individuals with Williams syndrome, a neurogenetic condition caused by deletion of a set of genes at chromosomal location 7q11.23, exhibit a remarkable suite of traits including hypersociality with high, nonselective friendliness and low social anxiety, expressive language relatively well-developed but under-developed social-communicatio...
Article
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Social interactions are central to most animals and have a fundamental impact upon the phenotype of an individual. Social behavior (social interactions among conspecifics) represents a central challenge to the integration of the functional and mechanistic bases of complex behavior. Traditionally, studies of proximate and ultimate elements of social...
Article
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Visiting multiple locations and returning to the start via the shortest route, referred to as the traveling salesman (or salesperson) problem (TSP), is a valuable skill for both humans and non-humans. In the current study, pigeons were trained with increasing set sizes of up to six goals, with each set size presented in three distinct configuration...
Article
Imprinted genes have been posited to have important roles in human brain development and cognition, but their effects in nonclinical populations have yet to be investigated. Single-nucleotide polymorphisms (SNPs) of the imprinted gene LRRTM1 have previously been associated with schizophrenia risk and with handedness in individuals with dyslexia. We...
Article
While consanguineous marriage has been shown to result in a small increase in risk of recessive Mendelian disorders among offspring, far less research has been conducted on the effects of inbreeding on complex traits. These effects, thought to result from increased developmental instability due to loss of heterozygosity, are expected to be found mo...
Article
The study of reliability, or ‘honesty’, in communication between individuals with conflicting interests has been a major focus of game theoretical modelling in evolutionary biology. It has been proposed that mixed populations of honest and deceptive signallers can be evolutionarily stable in a model of conventional, or ‘minimal cost’, signals of co...
Article
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postulated the existence of 'genes underlying altruism', under the rubric of inclusive fitness theory, a half-century ago. Such genes are now poised for discovery. In this article, we develop a set of intuitive criteria for the recognition and analysis of genes for altruism and describe the first candidate genes affecting altruism from social insec...
Article
Cerebral lateralization, the preferential use of one hemisphere of the brain to perform certain cognitive functions, is a widespread and evolutionarily ancient adaptation. Lateralization appears to enhance cognitive capacity, yet substantial individual variation in the strength cerebral lateralization is apparent in all species studied so far. It i...
Article
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Both autism spectrum conditions (ASCs) and schizophrenia spectrum conditions (SSCs) involve altered or impaired social and communicative functioning, but whether these shared features indicate overlapping or different etiological factors is unknown. We outline three hypotheses (overlapping, independent, and diametric) for the possible relationship...
Article
Both autism spectrum conditions (ASCs) and schizophrenia spectrum conditions (SSCs) involve altered or impaired social and communicative functioning, but whether these shared features indicate overlapping or different etiological factors is unknown. We outline three hypotheses (overlapping, independent, and diametric) for the possible relationship...
Article
Schizophrenia risk alleles are expected to mediate effects on cognitive task performance, and aspects of personality including schizotypy, in nonclinical populations. We investigated how 32 of the best-validated schizophrenia risk alleles, singly and as summed genetic risk, were related to measures of schizotypal personality and measures of two asp...
Article
Full-text available
Environmental sex determination (ESD) is one of the most striking examples of phenotypic plasticity. Individuals from species that exhibit ESD can develop as either males or females depending on the particular environmental conditions they experience during early development. In fish, ESD species often show a relatively subtle effect of environment...
Article
Gonadotropin-releasing hormone (GnRH) expressing neurons in the preoptic area (POA) of the hypothalamus plays a key role in regulating reproductive function through the control of gonadotropin release. Several studies have illustrated the importance of the social environment in modulating the size of GnRH expressing neurons. In the African cichlid...
Article
The 2D:4D digit ratio, the relative lengths of the index and ring fingers in humans, is a widely used proxy measure for prenatal testosterone exposure. Varying distributions of androgen and estrogen receptors on the second and fourth digits, both of which regulate digit development, appears to be the basis for this effect. Polymorphism in a tandem...
Article
Full-text available
Cerebral lateralization, the partitioning of cognitive function preferentially into one hemisphere of the brain, is a trait ubiquitous among vertebrates. Some species exhibit population level lateralization, where the pattern of cerebral lateralization is the same for most members of that species; however, other species show only individual level l...
Article
Full-text available
Cerebral lateralisation, the partitioning of cognitive functioning into one hemisphere of the brain, was once considered unique to humans; however, recent research in a variety of taxa suggests that lateralisation is an evolutionarily ancient adaptation. Handedness is the most obvious manifestation of cerebral lateralisation in humans. Much of the...
Article
Full-text available
Variation in prenatal exposure to androgens is thought to be responsible for some of the individual differences in aggressive behavior among adults. A putative indicator of prenatal testosterone exposure, 2D:4D (the index to ring finger length) ratios have shown a weak correlation with aggression. Variation in sensitivity of the androgen receptor,...
Article
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Black-capped (Poecile atricapillus) and mountain chickadees (Poecile gambeli) have been used as a model to examine cognitive functions including perception, episodic-like memory, and spatial learning and orientation. Recently, these species have been used in two studies to examine the relationship between learning and novel environment exploration...
Article
Cerebral lateralization was once thought to be unique to humans, but is now known to be widespread among the vertebrates. Lateralization appears to confer cognitive advantages upon those that possess it. Despite the taxonomic ubiquity and described advantages of lateralization, substantial individual variation exists in all species. Individual vari...
Article
Recent developments in ecological statistics have reached behavioral ecology, and an increasing number of studies now apply analytical tools that incorporate alternatives to the conventional null hypothesis testing based on significance levels. However, these approaches continue to receive mixed support in our field. Because our statistical choices...
Article
The lateralization of emotion has been described in a variety of animals. The right hemisphere has been implicated in the processing of negative emotions while positive emotions are processed in the left. Most animal studies of this phenomenon to date have used intrinsically emotionally arousing stimuli and there are few examples of lateralized res...
Article
Cerebral lateralization, the partitioning of cognitive tasks to one cerebral hemisphere, is a widespread phenomenon among vertebrates. Despite this diversity, every species studied to date shows substantial individual variation in the strength of lateralization. The neural basis of this trait is unclear, although asymmetries in cerebral structures...
Article
Individual variation in exploratory behaviour has been demonstrated in a diverse array of animal species. Understanding the evolutionary antecedents and ecological consequences of this variation is an active research area within animal behaviour. Here we investigate whether different exploration styles exhibited by black-capped chickadees (Poecile...
Article
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Convict cichlids (Archocentrus nigrofasciatus) are a territorial, monogamous, and biparental Central American cichlid fish. Convicts exist in two common color morphs: the wild-type (WT) black-barred form and an amelanistic (AM) barless morph. Color morphs affect aggressive interactions in other species of fish. We staged fights between males of eac...
Article
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Evolutionary psychologists have argued that the emergence of language was associated with reducing direct physical aggression and easing social functioning in small groups. If this is so, then males should use verbal or indirect aggression more frequently than females since they engage in more direct aggression. A recent study found no significant...
Article
Sir Philip Sidney games are a widely used model of simple signaling. Johnstone and Grafen [Johnstone, R.A., Grafen, A., 1993. Dishonesty and the handicap principle. Animal Behaviour 46, 759-764] present a version in which the Evolutionarily Stable Strategy (ESS) is for most signalers to "honestly" signal, with a small minority of signalers who "che...
Article
Full-text available
The second to fourth digit ratio (2Dratio4D) is sexually differentiated in a variety of species, including humans, rats, birds, and lizards. In humans, this ratio tends to be lower in males than in females. Lower digit ratios are believed to indicate increased prenatal testosterone exposure, and are associated with more masculinized behavior across...
Article
Full-text available
Cerebral lateralization is an evolutionarily ancient adaptation, apparently ubiquitous among vertebrates. Despite demonstrated advantages of having a more lateralized brain, substantial variability in the strength of lateralization exists within most species. The underlying reasons for the maintenance of this variation are largely unknown. Here, we...
Article
Full-text available
Anogenital distance (AGD) and the ratio of the second (index) to fourth (ring) digit lengths (2D:4D) are two widely used indicators of prenatal androgen exposure. The former is commonly used in rodent models, while the latter is principally used in human studies. We investigated variation in these two traits in C57BL/6J mice to test the hypothesis...
Article
Full-text available
The ratio of the length of the second digit (index finger) divided by the fourth digit (ring finger) tends to be lower in men than in women. This 2D:4D digit ratio is often used as a proxy for prenatal androgen exposure in studies of human health and behavior. For example, 2D:4D ratio is lower (i.e. more "masculinized") in both men and women of gre...
Article
Game theory is not only the primary method for the formal modelling of interactions between individuals, but it also underlies how biologists think about social interactions on an intuitive level. Most biologists equate game theory with the notion of an evolutionary stable strategy (ESS). Maynard Smith's definition of an ESS formalized an intuitive...
Article
Animals of many species use the geometric shape of an enclosed rectangular environment to reorient, even in the presence of a more informative featural cue. Manipulating the rearing environment affects performance on spatial tasks, but its effect on the use of geometric versus featural navigational cues is unknown. Our study varied the geometric in...
Article
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Comments on an article by J. C. Loehlin, D. McFadden, S. E. Medland and N. G. Martin (see record 2007-07455-014). The authors investigated the relationship between latitude and digit ratio (2D:4D). Like digit ratio, height has been suggested to reflect physical masculinization. Height is also positively correlated with perceptual-verbal ability (in...
Article
Full-text available
Despite the highly conserved circuitry of the cerebellum, its overall shape varies significantly among and within vertebrate classes. In birds, one of the most prominent differences among orders is the relative size of the cerebellar folia. The enlargement/reduction of individual folia is thought to relate to specific behavioral differences among t...
Article
Empirical evidence suggests that aggressiveness (willingness to enter into, or escalate an aggressive interaction) may be more important than the ability to win fights in some species. Both empirical and theoretical traditions treat aggressiveness as a distinct property from the ability (RHP) or motivation (subjective resource value) to win a fight...