Netzin G. Steklis

Interests

Teaching

• Human-animal interrelationships• Human-animal bond• Captive primate management• Animal ethology • Animal welfare

Research

• Human-animal interrelationships• Animal personality & life history• Evolution & biopsychology of human-animal interrelationships• Efficacy of animal assisted therapies

Courses

Scholarly Contributions

Books

• Steklis, H. D., & Steklis, N. G. (2020). Human and Animal Interrelationships (2nd Edition). Dubuque, Iowa: Kendall-Hunt Publishing Company.
  More info

  This book examines the relationships of humans with animals throughout theages. From our evolutionary past through domestication, the relationships of animals with humans throughout Europe and the New World are chronicled. Modern human-animal relationships will also be examined and analyzed and compared to those of ancient and historical times.Throughout, we take takes a science-based, multi-disciplinary approach to understanding the nature, diversity and functions of human-animal relationships that have developed over time, geographic region, and cultural contexts. This approach puts into fresh perspective many present developments, issues and challenges in the human-animal relationship, including the effectiveness of animal-assisted therapies, animal welfare and rights, animal experimentation, trophy hunting, wildlife management and conservation, and meat production industry.
• Steklis, H. D., & Steklis, N. G. (2020). Human-Animal Interrrelationships (Second Edition). Dubuque, Iowa: Kendall-Hunt Publishing Company.
• Steklis, H. D., & Steklis, N. G. (2016). Human and Animal Interrelationships (1st Edition). Dubuque, Iowa: Kendall-Hunt Publishing Company.
  More info

  This book examines the relationships of humans with animals throughout theages. From our evolutionary past through domestication, the relationships of animals with humans throughout Europe and the New World are chronicled. Modern human-animal relationships will also be examined and analyzed and compared to those of ancient and historical times.Throughout, we take takes a science-based, multi-disciplinary approach to understanding the nature, diversity and functions of human-animal relationships that have developed over time, geographic region, and cultural contexts. This approach puts into fresh perspective many present developments, issues and challenges in the human-animal relationship, including the effectiveness of animal-assisted therapies, animal welfare and rights, animal experimentation, trophy hunting, wildlife management and conservation, and meat production industry.
• Steklis, H. D., & Steklis, N. G. (2014). Men, Fatherhood and Families: A Biocultural Perspective, revised 1st edition. Cognella Academic Publishing.
  More info

  This is an edited work with authors' Introduction. This 1st edition is a revision of the "preliminary edition" published the previous year.

Chapters

• Steklis, H. D., & Steklis, N. G. (2021). An HAI Love Story: A couple collaborates as teachers and researchers exploring our connection to animals. In Career Paths in Human-Animal Interaction for Social and Behavioral Scientists. Routledge.
• Steklis, N. G., & Steklis, H. D. (2008). The Value of Long-Term Research: The Mountain Gorilla as a Case Study. In Conservation in the 21st Century: Gorillas as a Case Study. Springer US. doi:10.1007/978-0-387-70721-1_6

Journals/Publications

• Gnanadesikan, G., Carranza, E., King, K., Flyer, A., Ossello, G., Smith, P., Steklis, N., Steklis, H., Connelly, J., Barnett, M., Gee, N., Tecot, S., & MacLean, E. (2024). Glucocorticoid response to naturalistic interactions between children and dogs. Hormones and Behavior, 161. doi:10.1016/j.yhbeh.2024.105523
  More info

  Although research has shown that pets appear to provide certain types of social support to children, little is known about the physiological bases of these effects, especially in naturalistic contexts. In this study, we investigated the effect of free-form interactions between children (ages 8–10 years) and dogs on salivary cortisol concentrations in both species. We further investigated the role of the child-dog relationship by comparing interactions with the child's pet dog to interactions with an unfamiliar dog or a nonsocial control condition, and modeled associations between survey measures of the human-animal bond and children's physiological responses. In both children and dogs, salivary cortisol decreased from pre- to post-interaction; the effect was strongest for children interacting with an unfamiliar dog (compared to their pet dog) and for the pet dogs (compared to the unfamiliar dog). We found minimal evidence for associations between cortisol output and behaviors coded from video, but children scoring higher on survey measures of the human-animal bond exhibited the greatest reductions in cortisol when interacting with dogs. Self-reported loneliness was not related to cortisol or the human-animal bond, but measures of both loneliness and the human-animal bond were higher among children who participated after the onset of the COVID-19 pandemic, relative to those who participated before the pandemic. This study builds on previous work that investigated potential stress-buffering effects of human-animal interaction during explicit stressors and demonstrates important physiological correlates of naturalistic interactions between children and dogs, similar to those that occur in daily life.
• Gnanadesikan, G., King, K., Carranza, E., Flyer, A., Ossello, G., Smith, P., Steklis, N., Steklis, H., Carter, C., Connelly, J., Barnett, M., Gee, N., Tecot, S., & MacLean, E. (2024). Effects of human-animal interaction on salivary and urinary oxytocin in children and dogs. Psychoneuroendocrinology, 169. doi:10.1016/j.psyneuen.2024.107147
  More info

  Oxytocin pathways are hypothesized to play important roles in human-animal interactions and may contribute to some benefits of these interspecific social relationships. We explored the effects of naturalistic interactions between children and dogs on oxytocin release in both species, as well as associations between methylation of the oxytocin receptor gene (OXTRm), social behavior, and oxytocin response in this context. Children (N = 55) participated in a within-subjects design involving a) interaction with their pet dog, b) interaction with an unfamiliar dog, and c) a nonsocial control condition (solitary play). We used immunoassays to measure salivary and urinary oxytocin in both the children and dogs, behavioral coding to characterize dog-child interactions, and bisulfite sequencing to quantify methylation of the oxytocin receptor gene (N = 32 children). Child salivary oxytocin decreased moderately across time in all conditions, but the extent of this effect varied between conditions, with greater oxytocin output during interactions with dogs than the control condition. In the pet dog condition, children's salivary oxytocin response was positively associated with the duration of visual co-orientation between the child and dog. Child urinary oxytocin did not deviate substantially from baseline in any condition. Children with higher levels of OXTRm had greater oxytocin output during interactions with their pet dogs, but lower oxytocin output in the control condition, and engaged in lower levels of affectionate interaction with dogs across conditions. Children's pet dogs exhibited increases in salivary oxytocin, but we observed the opposite pattern in the unfamiliar dog, who exhibited decreases in both urinary and salivary oxytocin on average. Collectively, our results support the hypothesis that oxytocin pathways may shape and respond to social interactions between children and dogs, highlighting an important role for companion animals in child development.
• Steklis, N., Salmon, C., Steklis, H., Figueredo, A., & Peñaherrera-Aguirre, M. (2024). Dimensions of Animality: Expanding nomological breadth and controlling phenotypic similarity. Personality and Individual Differences, 223. doi:10.1016/j.paid.2024.112612
• Steklis, N., Steklis, H., Herrera, I., & Peñaherrera-Aguirre, M. (2024). Why Were Zebras Not Domesticated? A Review of Domesticability Traits and Tests of Their Role in Ungulate Domestications with Macroevolutionary Models. Animals, 14(16). doi:10.3390/ani14162355
  More info

  Since Darwin, many evolutionary and behavioral researchers have considered the role of phenotypic traits that favor the domestication of nonhuman animals. Among such proposed traits are a species’ social structure, level of intra- and interspecific agonistic interactions, sociosexual behaviors, parental strategies, reaction to humans, habitat preference, dietary habits, developmental trajectories, and utility to humans. However, little to no comparative phylogenetic evidence exists concerning the importance of these attributes for the domestication of animals. Moreover, rather than considering domestication as a dichotomous event (non-domesticated vs. domesticated), humans and their potential domesticates encountered numerous socioecological challenges/obstacles during the domestication process before reaching the stage of full domestication. The present study explored the influence of adult body mass, gregariousness, dietary breadth, and reaction to humans on the domestication process of ungulates. The phylogenetic comparative model revealed that capture myopathy (CM), as a proxy for reaction to humans, negatively and significantly influenced the domestication process. The present paper also explored the evolution of CM in equine species in response to the presence of large carnivoran predators during the Pleistocene. Ecologies that preserved most of the large carnivoran predators of equine species also featured more equine taxa with CM (e.g., zebras), which were thus less suitable for domestication.
• Figueredo, A., Salmon, C., Steklis, N., & Peñaherrera-Aguirre, M. (2023). The Relation of Clade-Specific Biophilia to the Construct of Animality. Evolutionary Psychological Science, 9(3). doi:10.1007/s40806-023-00360-5
  More info

  The main purpose of this study was to examine whether the nonhuman animal affinities described by the proposed psychometric construct of Animality might be distributed unequally across different kinds of animals. Thus, we explored how respondent Animality scores correlated with clade-specific self-reports of cognitive and emotional empathy toward specific animal categories. To do so, we applied the Concentric Circles Model, three concentric circles of nonhuman animal clades based on their figurative outwards distance from humanity: Kith and Kin Animals, including kith clades such as dogs and cats as well as kin clades such as primates; Domestic Animals, including cows, pigs, sheep, and goats; and Wild Animals, including catfish, carp, snakes, and spiders. Undergraduate participants from a Southwestern university completed a survey assessing their levels of Animality as well as their attitudes toward nonhuman animals from all three concentric circles. These data replicated the previously published hierarchical latent structure of Animality. The higher-order General Factor of Animality (GFA) loaded positively onto two lower-order factors: Attraction to Animals and Emotional Regard for Animals. The GFA was most highly positively correlated with Kith and Kin Animal Cognitive-Emotional Empathy, less highly correlated with Domestic Cognitive-Emotional Empathy, and least highly correlated with Wild Cognitive-Emotional Empathy; the GFA was also positively correlated with General Animal Harm Avoidance. In this sense, Animality seems to capture significant aspects of Clade-Specific Biophila in a manner consistent with the Concentric Circles Model.
• Figueredo, A., Steklis, N., Salmon, C., & Peñaherrera-Aguirre, M. (2023). The role of cross-species relative brain size variation and time since domestication in explaining human empathy towards domesticated mammals. Personality and Individual Differences, 200. doi:10.1016/j.paid.2022.111914
  More info

  Although multiple publications have addressed the nexus between individual differences and attitudes towards nonhuman animals, fewer studies have discussed the rise of human-animal interactions, in particular with domesticated mammals, through an evolutionary lens. Two evolutionary hypotheses, the Symbiotic and Neurocognitive hypothesis, provide complementary predictions regarding the evolution of these cognitive and emotional mechanisms. According to the Symbiotic hypothesis, the longer the time humans have had to interact symbiotically with domesticated the animals, the greater their empathy towards them. Alternatively, the Neurocognitive hypothesis argues that human empathy directed at animals increases in response to the neural and cognitive complexity of nonhuman animals. To test these hypotheses, the present study reported questionnaire data from 322 Southwestern university students. These psychometric instruments measured the participants' levels of cognitive empathy (the attribution of mental states to animals), emotional empathy (emotional concern about animals), and harm avoidance (reluctance to mistreat animals) when rating 13 domesticated mammals. The species' times since domestication and relative brain sizes were then used as predictors of cognitive empathy, emotional empathy, and harm avoidance. The results of Linear Mixed and Hierarchical General Linear Cascade Models found empirical support for the Symbiotic and Neurocognitive hypotheses.
• Steklis, H. D., Steklis, N. G., Peñaherrera-Aguirre, M., & Figueredo, A. J. (2023).

  Human-animal interactions from an evolutionary perspective: Symbioses as extended ultrasociality

  . Human-Animal Interactions. doi:10.1079/hai.2023.0028
• Aragonés, J. I., Araya, S. F., Armenta, M. F., Chaves, M. G., Fernandes, H. B., Figueredo, A. J., Peñaherrera-Aguirre, M., Pérez-Ramos, M., Salmon, C., Sevillano, V., Steklis, N. G., Verdugo, V. C., & de, T. C. (2022).

  The influence of individual differences and local ecological conditions on emotional empathy, cognitive empathy, and harm avoidance towards nonhuman animals

  . Human-Animal Interactions, 2022. doi:10.1079/hai.2022.0021
• Figueredo, A., Steklis, N., Fernandes, H., Cabeza de Baca, T., Salmon, C., Araya, S., Corral-Verdugo, V., Sevillano, V., Aragonés, J., Frías-Armenta, M., Hernández-Chaves, M., Peñaherrera-Aguirre, M., & Pérez-Ramos, M. (2022). The Adapa Tablets and the Tuxtla Glyphs: Coevolution Between Human and Nonhuman Animals. Evolutionary Psychological Science, 8(3). doi:10.1007/s40806-022-00320-5
  More info

  The purpose of this study was to examine how attitudes toward different nonhuman animal species (including emotional empathy, cognitive empathy, and harm avoidance) are shaped by the coevolutionary histories between the ancestors of contemporary humans and these different nonhuman animal species. We compared the explanatory power of alternative categorization frameworks for classifying attitudes toward animals across several cross-cultural samples (Arizona, California, Costa Rica, Spain, and Mexico). Analytical Approach 1 directly compared two alternative frameworks. Adapa categories were generated as purely functional ones based upon the ecological niches occupied by each species within the biotic community generated by human–nonhuman animal relations, and Tuxtla categories were generated as cognitive ones based upon the degrees of consciousness commonly ascribed to the constituent species. Analytical Approach 2 tested the alternative hypothesis that both categories were part of a general scheme organized into three superordinate categories reflecting concentric circles around our own, consistent with fitness interdependence theory. Results supported this alternative hypothesis. The concentric circles model (Kith & Kin Animals, Domesticated Animals, and Wild Animals) better explained empathy and harm avoidance scores, suggesting that attitudes toward specific animal species are partly shaped by which circles they fall into, the product of the coevolutionary relationship shared between them and humans.
• Smith, R., Steklis, H., Steklis, N., Weihs, K., Allen, J., & Lane, R. (2022). Lower Emotional Awareness Is Associated With Greater Early Adversity and Faster Life History Strategy. Evolutionary Behavioral Sciences, 17(1). doi:10.1037/ebs0000282
  More info

  Recent theoretical work suggests that emotional awareness (EA) depends on the harshness/predictability of early social interactions—and that low EA may in fact 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 article, 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 2 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 (a) general reflective cognition, and (b) emotional support from parents during childhood. This suggests that variations in EA may arise during development based on the benefits of cognitive reflection in environments with different levels of harshness and social predictability
• Steklis, N. G. (2021). Lower emotional awareness is associated with greater early adversity and faster life history strategy. Evolutionary Behavioral Sciences.
• Smith, R., Steklis, H. D., Steklis, N. G., Weihs, K. L., & Lane, R. D. (2020). The evolution and development of the uniquely human capacity for emotional awareness: A synthesis of comparative anatomical, cognitive, neurocomputational, and evolutionary psychological perspectives. Biological psychology, 154, 107925.
  More info

  We offer an interdisciplinary framework for understanding the expanded capacity for emotional awareness (EA) in humans relative to other animals, synthesizing work within computational neuroscience, evolutionary psychology, and comparative anatomy. We argue that disproportionate cortical expansion during human evolution reflects additional hierarchical levels of computational processing, allowing representation of multimodal regularities over longer timescales - affording abstract concept learning, internal simulation of distal future outcomes, and expanded working memory capacity. This allows for the ability to simulate emotions, learn emotion concepts, and manipulate them in working memory when deciding how to act. We also draw on the construct of life history strategy within evolutionary psychology to argue that individual differences in EA within humans can be understood as the result of tuning particular computational parameters to the predictability of long timescale socioemotional regularities of the local environment. We conclude by discussing the implications and testable hypotheses offered by our proposed framework.
• Cronk, L., Steklis, H. D., Steklis, N. G., van den Akker, O., & Aktipis, A. (2018). Kin terms and fitness interdependence. Evolution and Human Behavior, 40, 218-291. doi:https://doi.org/10.1016/j.evolhumbehav.2018.12.004
  More info

  Although genetic relatedness has been shown to be an important determinant of helping and other forms ofcooperation among kin, it does not correspond well to the different types of kin designated by the kin terminologiesused in human societies. This mismatch between genetic relatedness and kin terms has led someanthropologists to reject the idea that kin terms have anything to do with genetic relatedness or anything elsebiological. The evolutionary and cultural anthropological approaches can be reconciled through an appreciationof the concept of fitness interdependence, defined as the degree to which two or more organisms positively ornegatively influence each other's success in replicating their genes. Fitness interdependence may arise for avariety of reasons, including not only genetic relatedness but also mating and marriage, risk-pooling, mutual aid,and common group membership. The major kin term systems correspond to cross-culturally variable but recurrentpatterns of fitness interdependence among different types of kin. In addition, changes from one kin termsystem to another are associated with corresponding changes in recurrent patterns of fitness interdependenceamong kin, and kin terms are often used metaphorically in situations in which fitness interdependence has arisenamong non-kin.
• Cronk, L., Steklis, H. D., Steklis, N. G., van den Akker, O., & Aktipis, A. (2019). Kin terms and fitness interdependence. Evolution and Human Behavior, 40, 218-291. doi:https://doi.org/10.1016/j.evolhumbehav.2018.12.004
  More info

  Although genetic relatedness has been shown to be an important determinant of helping and other forms of cooperation among kin, it does not correspond well to the different types of kin designated by the kin terminologies used in human societies. This mismatch between genetic relatedness and kin terms has led some anthropologists to reject the idea that kin terms have anything to do with genetic relatedness or anything else biological. The evolutionary and cultural anthropological approaches can be reconciled through an appreciation of the concept of fitness interdependence, defined as the degree to which two or more organisms positively or negatively influence each other's success in replicating their genes. Fitness interdependence may arise for a variety of reasons, including not only genetic relatedness but also mating and marriage, risk-pooling, mutual aid, and common group membership. The major kin term systems correspond to cross-culturally variable but recurrent patterns of fitness interdependence among different types of kin. In addition, changes from one kin term system to another are associated with corresponding changes in recurrent patterns of fitness interdependence among kin, and kin terms are often used metaphorically in situations in which fitness interdependence has arisen among non-kin.
• Kogan, L., Germone, M., Steklis, H. D., Steklis, N. G., LaFollette, M. R., & Erdman, P. (2018). Guide to Human-Animal Interaction Education. Human-Animal Interaction Bulletin, 6, 37-46.
  More info

  Pursuing 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.
• Steklis, N. G., Eckardt, W., Fletcher, A. W., Steklis, H. D., Stoinski, T. S., & Weiss, A. (2015).

  Personality dimensions and their behavioral correlates in wild Virunga mountain gorillas (Gorilla beringei beringei).

  . Journal of comparative psychology (Washington, D.C. : 1983), 129(1), 26-41. doi:10.1037/a0038370
  More info

  Studies of animal personality improve our understanding of individual variation in measures of life history and fitness, such as health and reproductive success. Using a 54 trait personality questionnaire developed for studying great apes and other nonhuman primates, we obtained ratings on 116 wild mountain gorillas (Gorilla beringei beringei) monitored by the Dian Fossey Gorilla Fund's Karisoke Research Center in Rwanda. There were 8 raters who each had more than 1.5 years of working experience with the subjects. Principal component analyses identified 4 personality dimensions with high interrater reliabilities-Dominance, Openness, Sociability, and Proto-Agreeableness-that reflected personality features unique to gorillas and personality features shared with other hominoids. We next examined the associations of these dimensions with independently collected behavioral measures derived from long-term records. Predicted correlations were found between the personality dimensions and corresponding behaviors. For example, Dominance, Openness, Sociability, and Proto-Agreeableness were related to gorilla dominance strength, time spent playing, rates of approaches, and rates of interventions in intragroup conflicts, respectively. These findings enrich the comparative-evolutionary study of personality and provide insights into how species differences in personality are related to ecology, social systems, and life history.
• Steklis, H. D., & Steklis, N. G. (2011).

  Graduate Interdisciplinary Programs for Training Students in Human Behavior, Evolution, and Development

  . Human Ethology, 26(1). doi:10.22330/001c.89870
• Bradley, B. J., Robbins, M. M., Williamson, E. A., Steklis, H. D., Steklis, N. G., Eckhardt, N., Boesch, C., & Vigilant, L. (2005).

  Mountain gorilla tug-of-war: silverbacks have limited control over reproduction in multimale groups.

  . Proceedings of the National Academy of Sciences of the United States of America, 102(26), 9418-23. doi:10.1073/pnas.0502019102
  More info

  To determine who fathers the offspring in wild mountain gorilla groups containing more than one adult male silverback, we genotyped nearly one-fourth (n = 92) of the mountain gorillas (Gorilla beringei beringei) living in the Virunga Volcanoes region of Africa. Paternity analysis of 48 offspring born into four groups between 1985 and 1999 revealed that, although all infants were sired by within-group males, the socially dominant silverback did not always monopolize reproduction within his group. Instead, the second-ranking male sired an average of 15% of group offspring. This result, in combination with previous findings that second-ranking males fare best by not leaving the group but by staying and waiting to assume dominance even if no reproduction is possible while waiting, is not consistent with expectations from a reproductive skew model in which the silverback concedes controllable reproduction to the second-ranking male. Instead, the data suggest a "tug-of-war" scenario in which neither the dominant nor the second-ranking male has full control over his relative reproductive share. The two top-ranked males were typically unrelated and this, in combination with the mixed paternity of group offspring, means that multimale gorilla groups do not approximate family groups. Instead, as long-term assemblages of related and unrelated individuals, gorilla groups are similar to chimpanzee groups and so offer interesting possibilities for kin-biased interactions among individuals.

Presentations

• Steklis, H. D., & Steklis, N. G. (2016, June). Animality: How human-animal relationships have changed human nature. Seminar for faculty and students of the Clever Dog Laboratory, Univ. Vienna. University of Vienna, Austria: University of Vienna.
  More info

  Invited presentation.
• Steklis, H. D., & Steklis, N. G. (2016, November). The University of Arizona's Human-Animal Interaction Initiative. Purdue University Centers for the human-animal bond conference. Purdue University, Indiana: Purdue University Centers For the Human-Animal Bond (CHAB).
  More info

  Invited to participate in this two-day conference.
• Steklis, H. D., & Steklis, N. G. (2015, October). Animality and Human-Animal Kinship. Conference on "Kinship, Conflict and Cooperation: Reconceptualizing kinship for the 21st century". Berlin, Germany: Wissenschaftskolleg zu Berlin (WIKO).