Horst Steklis | The University of Arizona (original) (raw)

Papers by Horst Steklis

The craniocervical bite is a mode of predatory attack, directed to the head and/or neck of certai... more The craniocervical bite is a mode of predatory attack, directed to the head and/or neck of certain prey. It has been shown that smaller anthropoids, like other predatory mammals, display this pattern. Evidence reviewed here indicates that the pattern occurs in larger primates (chimpanzees and baboons) and in additional taxa, including lemuroids. The thesis that this pattern is phylogenetically old in the order Primates is strengthened by critical new data from two primate families for which there was previously little evidence.

Hormones and Behavior, Jun 1, 1985

The relationship of serum testosterone concentration to male dominance rank and frequency of aggr... more The relationship of serum testosterone concentration to male dominance rank and frequency of aggression was investigated in stable vervet monkey social groups, each containing two or three adult males, several adult females, and their offspring. Dominance relationships were determined by noting an animal's success in intermale aggressive encounters. A striking finding was the marked within-subject variation in testosterone concentration: 5- to 10-fold fluctuations were often observed on successive days. When all 15 groups were considered together, testosterone concentration was unrelated to dominance rank. Although mean testosterone concentration for all dominant males was higher than the mean for all subordinate males, this difference was not significant. In a subset of 4 groups, the rate of aggression initiated was significantly correlated with same-day testosterone in dominant but not in subordinate males.

Experimental Neurology, Oct 1, 1979

Electrical activity from the amygdaloid nucleus in freely moving monkeys (Cercopithecus aethiops)... more Electrical activity from the amygdaloid nucleus in freely moving monkeys (Cercopithecus aethiops) during social interactions and alone were recorded via radiotelemetry. Spectral analysis of amygdaloid activity revealed highest power outputs occurred during behaviors related to sexual and aggressive interactions and the lowest with the tension-reducing behavior of grooming. Power output was not directly related to motor activity. These results suggest that amygdaloid activity is related to the emotional significance and degree of ambiguity of an interaction. It is hypothesized that at least two separate tierent systems, one for low frequencies and the other for fast frequencies, may be correlated with different behavioral events.

American Journal of Primatology, 2006

Behavioral and Brain Sciences, Jun 1, 1980

Patterns in the data on human sexuality support the hypothesis that the bases of sexual emotions ... more Patterns in the data on human sexuality support the hypothesis that the bases of sexual emotions are products of natural selection. Most generally, the universal existence of laws, rules, and gossip about sex, the pervasive interest in other people's sex lives, the widespread seeking of privacy for sexual intercourse, and the secrecy that normally permeates sexual conduct imply a history of reproductive competition. More specifically, the typical differences between men and women in sexual feelings can be explained most parsimoniously as resulting from the extraordinarily different reproductive opportunities and constraints males and females normally encountered during the course of evolutionary history. Men are more likely than women to desire multiple mates; to desire a variety of sexual partners; to experience sexual jealousy of a spouse irrespective of specific circumstances; to be sexually aroused by the sight of a member of the other sex; to experience an autonomous desire for sexual intercourse; and to evaluate sexual desirability primarily on the bases of physical appearance and youth. The evolutionary causes of human sexuality have been obscured by attempts to find harmony in natural creative processes and human social life and to view sex differences as complementary. The human female's capacity for orgasm and the loss of estrus, for example, have been persistently interpreted as marriage-maintaining adaptations. Available evidence is more consistent with the view that few sex differences in sexuality are complementary, that many aspects of sexuality undermine marriage, and that sexuality is less a unifying than a divisive force in human affairs.

Language, Sep 1, 1978

Some people may be laughing when looking at you reading in your spare time. Some may be admired o... more Some people may be laughing when looking at you reading in your spare time. Some may be admired of you. And some may want be like you who have reading hobby. What about your own feel? Have you felt right? Reading is a need and a hobby at once. This condition is the on that will make you feel that you must read. If you know are looking for the book enPDFd origins and evolution of language and speech annals of the new york academy of sciences v 280 as the choice of reading, you can find here.

American Journal of Primatology, 1986

This study examined the relationship between dominance rank and several physiological and behavio... more This study examined the relationship between dominance rank and several physiological and behavioral measures in stable, captive, all‐male squirrel monkey groups. Four groups, each containing three males, were observed for 12 weeks during the breeding season. Relative dominance ranking among males in each group was based on the direction of agonistic behaviors displayed. For each subject, whole blood serotonin (WBS), plasma testosterone (T), and cortisol (C) were sampled 4 to 6 times over the course of the study. Samples were separated by 1‐ to 2‐week intervals. Each group had a stable linear dominance hierarchy. WBS had small intraanimal variance and was positively related to dominance rank. In contrast, T and C were highly variable within subjects and were unrelated to dominance rank. Among alpha males, concentrations of T and C were positively correlated, and WBS and C were negatively correlated. The effect of dominance rank on the relationship between within‐animal fluctuations in WBS, T, and C and behavior was also assessed. In dominant, but not subordinate subjects, intraanimal fluctuations in WBS correlated with agonistic behavior initiated, and fluctuations in C and T correlated with huddling. In beta and gamma males, C was related to agonism received, and in gamma males to food stealing received. Dominance status also affected endocrine response to the stress of capture but not the rate of sneezing. Sneezing was positively correlated with T concentrations irrespective of dominance rank. These results extend the association between WBS and dominance rank previously reported in Old World monkeys to a New World monkey species, support previous suggestions that mean T and C titers are not reflective of dominance rank in well‐established groups, and indicate that dominance rank affects adrenocortical response to the stress associated with capture and anesthesia.

Journal of Human Evolution, Feb 1, 1985

When nearly a decade ago I began to give the question of language origins serious attention, I wa... more When nearly a decade ago I began to give the question of language origins serious attention, I was convinced, like many others pondering this problem, that there were no particularly appealing or promising similarities between human speech and the natural communication systems of non-human primates. Indeed, the chasm separating human language from non-human communication appeared so great that any speculation on the evolution of language had to consider how qualitatively new perceptual, cognitive, and motor abilities arose in the human lineage. In very simple terms, the information content of non-human communication signals was believed to be relatively poor and the repertoire a genetically fixed, closed one (cf. Hockett, 1960). Unlike human language, the signals of other species informed only about the signalter's location and emotional-motivational state, such as hunger, fear, or sexual arousal. In this view, such signalling behavior lacks the propositional, referential, and symbolic features that are an integral part of human *This article is based on a paper presented at the Symposium On Origins of Language, in the

Brain Behavior and Evolution, 1976

Human-Animal Interactions

The field of human-animal interactions (HAI) is focused primarily on human-companion animal relat... more The field of human-animal interactions (HAI) is focused primarily on human-companion animal relationships, especially the impact of such relationships on human health. Here, we demonstrate how a wider, integrative approach, consisting of an evolutionary framework, provides new insights into the varieties of HAIs and their emergence and significance during human evolution. Along with other HAI researchers, we show that those HAIs which develop into interrelationships can best be treated as ecological symbioses that involve fitness interdependence among the symbionts and entail the evolution of phenotypic traits that support the adaptive features of the symbionts. We present the novel idea that the formation of mutualistic symbiotic relationships through the process of domestication depended on the prior evolution of hominin hypersociality and ultrasociality in modern humans. Hypersociality was characterized by high levels of social cooperation and social tolerance that became increas...

Human-animal interaction bulletin

Pursuring a career in human-animal interaction (HAI) may feel daunting, as this field is quickly ... more Pursuring a career in human-animal interaction (HAI) may feel daunting, as this field is quickly growing and changing, and offers a wide array of career possibilities with pathways and educational programs. Yet, it is this broad scope of possibilities that can make navigating the field challenging. The purpose of this article is to help guide individuals who are interested in exploring a career with animals and humans. Our specific aims are to (a) describe and define the current field of HAI, (b) synthesize possible human-animal studies programs as provided by the Animals and Society website, and (c) offer guidance for those interested in exploring HAI careers. This paper, is designed as a practical guide to help students and their mentors navigate the HAI field.

The craniocervical bite is a mode of predatory attack directed at the head and/or neck of the pre... more The craniocervical bite is a mode of predatory attack directed at the head and/or neck of the prey. It is prominent in nonhuman primates and is apparently innate and phylogenetically old. The hypothesis that the craniocervical bite will also be prominent in primate infanticide is supported by data from ten genera in four primate families. This result raises complex issues about the proximal mechanisms underlying the craniocervical bite. The presence of the bite in primate infanticide casts a light on the nature of the innate mechanism.

Recent theoretical work suggests that emotional awareness (EA) depends on the harshness/predictab... more Recent theoretical work suggests that emotional awareness (EA) depends on the harshness/predictability of early social interactions – and that low EA may actually be adaptive in harsh environments that lack predictable interpersonal interactions. In evolutionary psychology, this process of psychological “calibration” to early environments corresponds to life history strategy (LHS). In this paper, we tested the relationship between EA and LHS in 177 (40 male) individuals who completed the levels of emotional awareness scale (LEAS), Arizona Life History Battery (short form: K-SF-42), and two measures of early abuse/neglect. Significantly lower EA was observed in those with faster LHS and who had experienced greater early adversity. Notably, LEAS was associated with differences in 1) general reflective cognition, and 2) emotional support from parents during childhood. This suggests that EA may be learned during development based on the benefits of cognitive reflection in environments w...

Brain Connectivity, 2020

Evolutionary-developmental theories consider the evolved mechanisms underlying adaptive behaviora... more Evolutionary-developmental theories consider the evolved mechanisms underlying adaptive behavioral strategies shaped in response to early environmental cues. Identifying neurological mechanisms mediating processes of conditional adaptation in humans is an active area of research. Resting-state functional magnetic resonance imaging (RS-fMRI) captures functional connectivity theorized to represent the underlying functional architecture of the brain. This allows for investigating how underlying functional brain connections are related to early experiences during development, as well as current traits and behaviors. This review explores the potential of RS-fMRI of the amygdala for advancing research on the neurological mechanisms underlying adaptive strategies developed in early adverse environments. RS-fMRI studies of early life stress and amygdala functional connectivity within the frame of evolutionary theories are reviewed, specifically regarding the development of self-regulatory strategies. The potential of RS-fMRI for investigating the effects of early life stress on developmental trajectories of self-regulation is discussed.

We present an interdisciplinary framework for understanding the expanded capacity in humans (rela... more We present an interdisciplinary framework for understanding the expanded capacity in humans (relative to other animals) to be consciously aware of emotions (emotional awareness; EA). To do so, we provide a synthesis of many different bodies of work, including those on cognitive and computational neuroscience, evolutionary psychology, and comparative anatomy. Based on active inference models within computational neuroscience, we first argue that the disproportional expansion of association cortices in humans during evolution reflects additional hierarchical levels of processing that allow learning, inference, and simulation of multimodal regularities over longer timescales – affording abstract concept learning, the ability to internally simulate the distal future outcomes of actions, and an expanded working memory capacity. This increase in general reflective capacity then allows for emotion concept learning and the ability to simulate emotions and manipulate them in working memory w...

Proceedings in Life Sciences, 1982

This pre-Congress symposium at Pisa, Italy, in July 1980 brought together an international group ... more This pre-Congress symposium at Pisa, Italy, in July 1980 brought together an international group of scientists actively working in the areas of pharmacology and endocrinology, with particular emphasis on social behavior.

This peer-reviewed book series melds the facts of organic diversity with the continuity of the ev... more This peer-reviewed book series melds the facts of organic diversity with the continuity of the evolutionary process. The volumes in this series exemplify the diversity of theoretical perspectives and methodological approaches currently employed by primatologists and physical anthropologists. Specific coverage includes: primate behavior in natural habitats and captive settings; primate ecology and conservation; functional morphology and developmental biology of primates; primate systematics; genetic and phenotypic differences among living primates; and paleoprimatology.