by Hal Herzog
anthrozoologist James Serpell Serpell, J. A. (2004) Factors influencing human attitudes to animals and their welfare. Animal Welfare, 13, S145–151.
How Pigeons Became Rats Jerolmack, C. (2008). How pigeons became rats: The cultural-spatial logic of problem animals. Social Problems, 55, 72–94.
the croc’s death as “emotionally satisfying yet thoroughly irrational.” No author. (September 12, 1977). Kill the crocodile. New York Times (p. 32).
The debate over whether human morality is based on emotion or reason For an excellent overview of moral psychology, see Hauser, M. D. (2006). Moral minds: How nature designed our universal sense of right and wrong. New York: Harper Collins.
Shelley Galvin and I used this method to investigate how people make decisions about the use of animals in research Galvin, S. L., & Herzog, H. A. (1992). The ethical judgment of animal research. Ethics & Behavior, 2(4), 263–286.
Haidt’s theory Haidt, J. (2001). The emotional dog and its rational tail: A social intuitionist approach to moral judgment. Psychological Review, 108(4), 814–834.
Paul Rozin calls disgust the moral emotion Rozin, P., Haidt, J., & McCauley, C.R. (1999). Disgust: The body and soul emotion. In T. Dalgleish & M. Power(eds.), Handbook of cognition and emotion (pp. 429–445). Chichester, UK: Wiley.
causes the emotional processing centers of the brain to light up while the impersonal version (throwing the switch) does not For examples of Greene’s research on the neuroanatomy of morality see Greene, J., & Haidt, J. (2002). How (and where) does moral judgment work? Trends in Cognitive Sciences, 6(12), 517–523.
University of California psychologist Lewis Petrinovich Petrinovich, L., O’Neill, P., & Jorgenson, M. (1993). An empirical study of moral intuitions: Toward an evolutionary ethics. Journal of Personality and Social Psychology, 64(3), 467–478.
Marc Hauser, director of the Cognitive Evolution Laboratory Hauser, M. D. (2006). Moral minds: How nature designed our universal sense of right and wrong. New York: Harper Collins.
Richard Bulliet Bulliet, R. W. (2005). Hunters, herders, and hamburgers: The past and future of human-animal relationships. New York: Columbia University Press.
Answer these two questions The bat and ball question still drives me crazy. Think of it this way: If the bat cost $1 and the ball cost 10 cents, then the bat cost 90 cents more than the ball, not a dollar more. However, if the bat costs $1.05 and the ball costs 5 cents, then the bat costs a dollar more than the ball, and together they add up to $1.10. These examples are from Plous, S. (1993). The psychology of judgment and decision making. New York: McGraw-Hill.
Our predilection for revenge Sunstein, C. R. (October 2002). Hazardous heuristics. University of Chicago Law & Economics Olin Law and Economics Working Paper No. 165 and University of Chicago Public Law Research Paper No. 33.
heuristic is called framing The scientific literature on heuristic is vast. For examples, see Hallinan, J. T. (2009). Why we make mistakes. New York: Broadway Books. Marcus, G. (2008). Kluge: The haphazard construction of the human mind. New York: Houghton Mifflin. Kahneman, D., & Frederick, S. (2002). Representativeness revisited: Attribute substitution in intuitive judgment. In T. Gilovick, D. Grifin, & D. Kahneman (eds.), Heuristics and biases: The psychology of intuitive judgment (pp. 49–81). Cambridge, UK: Cambridge University Press.
the Nazi animal protection movement For an excellent description of the Nazi animal protection movement see Arluke, A., & Sax, B. (1992). Understanding Nazi animal protection and the Holocaust. Anthrozoös, 5(1), 6–31. Sax, B. (2000). Animals in the Third Reich: Pets, scapegoats, and the Holocaust. New York: Continuum International Publishing Group.
contemporary animal activists don’t relish the idea that Adolf Hitler was a fellow traveler See, for example, Berry, R. (2004). Hitler: Neither vegetarian nor animal lover. Brooklyn, NY: Pythagorean Books.
how children and adults responded to an AIBO compared to a real dog Melson, G. F., Kahn, P., Beck, A., Friedman, B., & Edwards, N. (2009). Robotic pets in human lives: Implications for the human-animal bond and for human relationships with personified technologies. Journal of Social Issues, 65, 545–567.
AIBO could also alleviate human loneliness Banks, M. R., Willoughby, L. M., & Banks, W. A. (2008). Animal-assisted therapy and loneliness in nursing homes: Use of robotic versus living dogs. Journal of the American Medical Directors Association, 9(3), 173–177.
Serpell eloquently lays out the moral issues Serpell, J. A. (1996). In the company of animals: A study of human-animal relationships. Cambridge, UK: Cambridge University Press. (p. 177).
Researchers at the University of Portsmouth Morris, P. H. (2008). Secondary emotions in non-primate species? Behavioural reports and subjective claims by animal owners. Cognition & Emotion, 22(1), 3–20.
“What Is It Like to Be a Bat?” Nagel, T. (1974). What is it like to be a bat? Philosophical Review, 4, 435–450.
what Gordon Burghardt calls critical anthropomorphism Burghardt, G. M (1991). Cognitive ethology and critical anthropomorphism: A snake with two heads and hognose snakes that play dead. In C. A. Ristau (ed.), Cognitive ethology: The minds of other animals (pp. 53–90). Hillsdale, NJ: Lawrence Erlbaum Associates. Not all animal behaviorists are enthusiastic about the emergence of anthropomorphism as an ethological research tool. See, for example, Wynne, C. D. L. (2004). The perils of anthropomorphism. Nature, 428, 606.
Assume that animal companions Holbrook, M. B. (2008). Pets and people: Companions in commerce. Journal of Business Research, 61, 546–552.
Antoine, a young Frenchman Gueguen, N., & Ciccotti, S. (2008). Domestic dogs as facilitators in social interaction: An evaluation of helping and courtship behaviors. Anthrozoös, 21, 339–349.
The historian Keith Thomas argues that pets are animals that are allowed in the house Thomas, K. (1983). Man and the natural world: A history of modern sensibility. New York: Pantheon.
University of Pennsylvania anthrozoologist James Serpell Serpell, J. A. Pet-keeping and animal domestication: A reappraisal. In Clutton-Brock, J. (ed.) (1989). The walking larder: Patterns of domestication, pastorialism and predation (pp. 10–21). London: Unwin Hyman.
most animals in American homes Grier, K. C. (2006). Pets in America: A history. Chapel Hill: University of North Carolina Press.
more like slavery Irvine, L. (2004). Pampered or enslaved? The moral dilemmas of pets. International Journal of Sociology and Social Policy, 24, 5–17. (p. 14).
the amount of money we dole out American Pet Products Association. (2009). Industry trends and statistics. Retrieved August 30, 2009, from americanpetproducts.org/press_industrytrends. asp. Brady, D., & Palmeri, C. (August 6, 2007). The pet economy. Business Week.
nineteenth-century France. Kete, K. (1995). The beast in the boudoir: Petkeeping in nineteenth-century Paris. Berkeley: University of California Press.
a trend that Michael Silverstein and Neil Fiske call trading up Silverstein, M. J., & Fiske, N. (2003). Trading up: Why consumers want new luxury goods—and how companies create them. New York: Portfolio.
answer is yes Some aspects of the pet industry have been more affected by the economic downturn than others. For example, according to James Serpell, the University of Pennsylvania Veterinary Hospital has seen a dramatic drop in expensive medical procedures for dogs and cats in the last two years.
advice to corporations trying to tap into the lucrative pet products marketplace Holbrook, M. B. (2008). Pets and people: Companions in commerce. Journal of Business Research, 61, 546–552.
benefits they derived from their relationships Herzog, H., Kowalski, R., Burgner, M., & Dunegon, C. (May 2003). Are pets really friends? Perceived benefits of relationships with companion animals. Paper presented at the meeting of the American Psychological Society, Atlanta, GA.
Human friends were better than animal companions Serpell, J. (1989). Humans, animals, and the limits of friendship. In Porter, R., & Tomaselli, S. (eds.), The dialectics of friendship (pp. 111–129). London: Routledge.
not particularly attached to their animals Johnson, T. P., Garrity, T. F., & Stallones, L. (1992). Psychometric evaluation of the Lexington Attachment to Pets Scale. Anthrozoös, 5, 160–175. A lot of research has focused on people who are attached to their pets. However, I don’t know of any systematic investigations of the millions of people who live with animals whom they dislike.
pet attachment drops a notch Poresky, R. H., & Daniels, A. M. (1998). Demographics of pet presence and attachment. Anthrozoös, 11, 236–241.
owning a pet made a big difference in their survival rates Friedmann, E., Katcher, A. H., Lynch, J. J., & Thomas, S. A. (1980). Animal companions and one-year survival of patients after discharge from a coronary care unit. Public Health Reports, 95(4), 307–312. Erica later replicated these effects, this time with more subjects so that the effects of owning dogs and cats could be evaluated separately. While owning a dog had a big effect on survivorship, owning a cat had no effect. See Friedmann, E., & Thomas, S. (1995). Pet ownership, social support, and one-year survival after acute myocardial infarction in the cardiac arrhythmia suppression trial (CAST). American Journal of Cardiology, 76, 1213–1217.
the notion that pets have beneficial effects on human health and well-being For reviews of this research see Friedmann, E., Thomas, S., & Eddy, T. (2000). Companion animals and human health: Physical and cardiovascular influences. In Podberscek, A. L., Paul, E. S., Serpell, J. A. (ed.), Companion animals and us: Exploring the relationships between people and pets (pp. 125–142). Cambridge, UK: Cambridge University Press. Wells, D. L. (2009). The effects of animals on human health and well-being. Journal of Social Issues, 65, 523–543. Beck, A. M., & Katcher, A. H. (2003). Future directions in human-animal bond research. American Behavioral Scientist, 47(1), 79–93. Barker, S. B., & Wolden, A. R. (2008). The benefits of human-companion animal interaction: A review. Journal of Veterinary Medical Education. 35, 487–495. Headey, B., & Grabka, M. M. (2007). Pets and human health in Germany and Australia: National longitudinal results. Social Indicators Research, 80(2), 297–311.
Karen Allen, a bio-psychologist at the University at Buffalo Allen, K. (2003). Are pets a healthy pleasure? The influence of pets on blood pressure. Current Directions in Psychological Science, 12(6), 236–239.
Chinese women who owned dogs Headey, B., Na, F., & Zheng, R. (2008) Pet dogs benefit owner’s health. A “natural experiment” in China. Social Indicators Research, 87(3), 481–493.
an article in my local paper recently claimed Clark, P. (2010) Wagging tail, wet nose brighten hospital. Asheville Citizen-Times. The reference for the radiation therapy study is Johnson, R. A., Meadows, R. L., Haubner, J. S., & Sevedge, K. (2008). Animal-assisted activity among patients with cancer: Effects on mood, fatigue, self-perceived health, and sense of coherence. Oncology Nursing Forum, 35, 225–232.
suffering from chronic fatigue syndrome Wells, D. L. (2009). Associations between pet ownership and self-reported health status in people suffering from chronic fatigue syndrome. Journal of Alternative and Complementary Medicine, 15, 407–413.
effects of dog-walking on fitness Cutt, H. E., Knuiman, M. W., & Giles-Corti, B. (2008). Does getting a dog increase recreational walking? International Journal of Behavioral Nutrition and Physical Activity, 5(17).
a study of 21,000 people in Finland Koivusilta, L. K., & Ojanlatva, A. (2006). To have or not to have a pet for better health? PLoS ONE, 1, 1–9.
Researchers at the Australian National University Parslow, R. A., Jorm, A. F., Christensen, H., Rodgers, B., & Jacomb, P. (2005). Pet ownership and health in older adults: Findings from a survey of 2,551 community-based Australians aged 60–64. Gerontology, 51(1), 40–47.
effects of acquiring a pet on loneliness in adults Gilbey, A., McNicholas, J., & Collis, G. M. (2007). A longitudinal test of the belief that companion animal ownership can help reduce loneliness. Anthrozoös, 20(4), 345–353.
the results of thirty studies Friedmann, E., & Son, H. (2009). The human-companion animal bond: How humans benefit. Veterinary Clinics of North America, 39(2) 293–326.
Pet ownership does seem to make some, but not all, people feel healthier and happier In anthrozoology, as in other areas of science, studies that show no effect are usually not published. This “file drawer effect” means that the published research probably exaggerates the actual effects of animals on human health. A recent study of twelve antidepressants found 33 of 36 experiments showing these drugs were ineffective were not published. Turner, E. H., Matthews, A. M., Linardatos, E., Tell, R. A., & Rosenthal, R. (2008). Selective publication of antidepressant trials and its influence on apparent efficacy. New England Journal of Medicine, 358(3), 252–260.
There are three possibilities McNicholas, J., Gilbey, A., Rennie, A., Ahmedzai, S., Dono, J. A., & Ormerod, E. (2005). Pet ownership and human health: A brief review of evidence and issues. British Medical Journal, 331(7527), 1252–1254.
Karen Allen did it—with rich stockbrokers no less Allen, K., Shykoff, B. E., & Izzo, J. L. (2001). Pet ownership, but not ACE inhibitor therapy, blunts home blood pressure responses to mental stress. Hypertension, 38(4), 815–820.
sixteen seniors were brought to a Sydney emergency room Kurrle, S. E., Day, R., & Cameron, I. D. (2004). The perils of pet ownership: A new fall-injury risk factor. Medical Journal of Australia, 181(11/12), 682–683.
Centers for Disease Control Centers for Disease Control (2009). Nonfatal fall-related injuries associated with dog and cats—United States, 2001–2006. MMWR Weekly, 58, 277–281.
Pets can be health hazards in other ways as well Some of the ways pets can be harmful are unusual. An article in the newsletter of the American Association of Reptile Veterinarians described eighteen cases of sexual aggression perpetuated by pet male iguanas toward their owners. Frye, F. F., Mader, D. R., & Centofanti, B. V. (1991). Interspecific (lizard: Human) sexual aggression in captive iguanas (Iguana iguana). American Association of Reptile Veterinarians, (1), 4–6.
humans are susceptible to zoonotic Pickering, L. K., Marano, N., Bocchini, J. A., & Angulo, F. J. (2008). Exposure to nontraditional pets at home and to animals in public settings: Risks to children. Pediatrics, 122(4), 876–886.
pet-related Salmonella is on the rise For a fascinating overview of diseases that humans can contract from animals, see Torrey, E. F., & Yolken, R. H. (2005). Beasts of the earth: Animals, humans, and disease. New Brunswick, NJ: Rutgers University Press.
75,000 cases of Salmonella Centers for Disease Control (2003) Reptile-Associated Salmonellosis—Selected States, 1998–2002. MMWR, 52(49) 1206–1209.
spread MSRA Lefebvre, S. L., & Weese, J. S. (2009). Contamination of pet therapy dogs with MRSA and Clostridium difficile. Journal of Hospital Infection, 72, 268–269. Enoch, D., Karas, J., Slater, J., Emery, M., Kearns, A., & Farrington, M. (2005). MRSA carriage in a pet therapy dog. Journal of Hospital Infection, 60(2), 186–188.
a wide variety of explanations for the human-animal bond These theories are discussed in Tuan, Y. (1984). Dominance affection: The making of pets. New Haven, CT: Yale University Press. Grier, K. C. (2006). Pets in America: A history. Chapel Hill: University of North Carolina Press.; Franklin, A. (1999). Animals and modern cultures: A sociology of human-animal relations in modernity. London: Sage.; Serpell, J. (1996). In the company of animals: A study of human-animal relationships. Cambridge, UK: Cambridge University Press. Irvine, L. (2004). If you tame me: Understanding our connection with animals. Philadelphia, PA: Temple University Press. Olmert, M. D. (2009). Made for each other: The biology of the human-animal bond. Philadelphia, PA: Da Capo Press.
Dan Gilbert of Harvard University claims that every psychologist Gilbert, D. (2006). Stumbling on happiness. New York: Alfred A. Knopf.
complex symbolic language, moral codes, religious beliefs, and the ability to learn to enjoy the burn of red hot chili peppers For an excellent overview of the factors that make our species unique see Gazzaniga, M. (2008). Human: The science behind what makes us unique. New
York: Harper Collins. For evidence that humans are the only mammal with the ability to learn to enjoy the burn of hot chilies, see Rozin, P., Gruss, L., & Berk, G. (1979). Reversal of innate aversions: Attempts to induce a preference for chili peppers in rats. Journal of Comparative and Physiological Psychology, 93(6), 1001–1014. There may be a few interesting exceptions. Rozin was able to teach two captive chimpanzees to like the taste of hot food. In addition, he found a few Mexican dogs that preferred piquant food. In all cases, these animals were raised as pets; Rozin believes that it was the social nature of the learning situation which enabled the animals to overcome natural taste aversions. Rozin, P., & Kenel, K. (1983). Acquired preferences for piquant foods by chimpanzees. Appetite, 4, 69–77.
The pair were practically inseparable You can watch the story of Tarra and Bella at www.elephants.com/tarra/TarraBella2.php.
raising young rhesus monkeys with adult dogs Mason, W. A., & Kenney, M. (1974). Redirection of filial attachments in rhesus monkeys: Dogs as mother surrogates. Science, 183(4130), 1209–1211.
the chimpanzee One incident has been used as evidence that chimps keep pets. The so-called pet was a hyrax, an animal that resembles a large guinea pig. In a scene reminiscent of King Kong, a team of Japanese primatologists working in Guinea observed a chimpanzee in a tree capture a hyrax, carefully carry it to the ground, and show it off to a couple of other chimps. Sounds like the start of a good relationship. But, just as in King Kong, things did not turn out well. The chimpanzee soon proceeded to smash the screaming hyrax against a tree trunk while his pals pummeled it with their fists until the little animal was dead. After poking the hyrax’s body around for a while, the apes got bored and casually tossed it into the bushes. The next morning, the researchers observed a female chimp grooming the hyrax’s corpse for ten minutes. The chimpanzees may have treated the hyrax like toy, but they certainly did not think of it as a pet. This incident is reported in Hirata, S., Yamakoshi, G., Fujita, S., Ohashi, G., & Matsuzawa, T. (2001). Capturing and toying with hyraxes (Dendrohyrax dorsalis) by wild chimpanzees (Pan troglodytes) at Bossou, Guinea. American Journal of Primatology, 53(2), 93–97.
