by Hal Herzog
best we can do is guess There is a debate about whether modern modes of thinking evolved abruptly because of a sudden change in a handful of genes or occurred much more gradually. Balter, M. (2002) What made humans modern? Science, 295, 1219–1225; Wade, N. (July 25, 2006). Nice rats, nasty rats: Maybe it’s all in the genes. New York Times. For discussions of the evolution of human cognitive abilities see Tomasello, M. (1999). The cultural origins of human cognition. Cambridge, MA: Harvard University Press; and Mithen, S. J. (1996). The prehistory of the mind: The cognitive origins of art, religion and science. London: Thames and Hudson. Serpell’s views are in Serpell, J. A. (2003). Anthropomorphism and anthropomorphic selection-beyond the “cute response.” Society & Animals, 11(1), 83–100.
orgasm in human females See, for example, Lloyd, E. A. (2005). The case of the female orgasm: Bias in the science of evolution. Cambridge, MA: Harvard University Press.
attribute of human nature that evolved See Serpell, J. (1996). In the company of animals: A study of human-animal relationships. Cambridge, UK: Cambridge University Press. (p. 148).
human universals Brown, D. E. (1991). Human universals. Philadelphia, PA: Temple University Press.; Pinker, S. (2002). The blank slate: The modern denial of human nature. New York: Viking.
By comparing the two types of twins Dunn, K. M., Cherkas, L. F., & Spector, T. D. (2005). Genetic influences on variation in female orgasmic function: A twin study. Biology Letters, 1(3), 260–263.; Silventoinen, K., Sammalisto, S., Perola, M., Boomsma, D. I., Cornes, B. K., Davis, C., et al. (2003). Heritability of adult body height: A comparative study of twin cohorts in eight countries. Twin Research and Human Genetics, 6(5), 399–408. Lykken, D., & Tellegen, A. (1996). Happiness is a stochastic phenomenon. Psychological Science, 7, 186–189.
Steven Pinker’s theory of music Pinker, S. (1997). How the mind works. New York: Norton.
nest parasitism, a reproductive strategy The idea that pets are a kind of nest parasitism is discussed by Serpell (1996) and by Archer, J. (1997). Why do people love their pets? Evolution and Human Behavior, 18(4), 237–259
Memes are everywhere To learn more about cultural evolution and memes see Shennan, S. (2002). Genes, memes and human history. London: Thames & Hudson; and Blackmore, S. (1999). The meme machine. Oxford, UK: Oxford University Press. The philosopher who has really taken Dawkins’s idea and run with it is Daniel Dennett (1995). Darwin’s dangerous idea: Evolution and the meanings of life. New York: Simon & Schuster. For a critical analysis of the meme idea see Richerson, P. J., & Boyd, R. (2005). Not by genes alone: How culture transformed human evolution. Chicago: University of Chicago Press.
raised with pets usually grow up to be pet-owning adults Anthropologists call the transmission of information from generation to generation “vertical” as compared to “horizontal transmission,” which is the spread of memes across a culture.
the pets of choice in Japanese homes Bulliet, R. W. (2005). Hunters, herders, and hamburgers: The past and future of human-animal relationships. New York: Columbia University Press.
Their smiles, wagging tails and kisses say it all. Email from Ruby Benjamin (August 10, 2009).
If dogs could talk This statement was uttered by Dylan during his XM satellite radio show, Theme Time Radio Hour. The topic of the show was songs about dogs.
genetic heritage runs 98% wolf and 2% dog In reality, the claims about the “percent wolf” in a wolf-dog are almost never confirmed by actual genetic testing.
Molecular biologists Heidi Parker and Elaine Ostrander Parker, H. G., & Ostrander, E. A. (2005). Canine genomics and genetics: Running with the pack. PLoS Genetics, 1(5), e58.
But when, where, and why did our ancestors For overviews of recent findings on the evolution of dogs see Miklósi, A. (2007). Dog behaviour, evolution, and cognition. Oxford, UK: Oxford University Press.
Paleolithic cave art is rife with stunning images Guthrie, R. D. (2005). The nature of Paleolithic art. Chicago: University of Chicago Press. There was a tendency for early artists to concentrate on large mammals that they preyed upon. However, the lack of images of dogs does suggest that they did not have them as pets. Bulliet, R. W. (2005). Hunters, herders, and hamburgers: The past and future of human-animal relationships. New York: Columbia University Press.
Domestication changes a species Clutton-Brock, J. (1995). Origins of the dog: Domestication and early history. In J. Serpell (ed.), The domestic dog: Its evolution, behaviour, and interactions with people (pp. 7–20). Cambridge, UK: Cambridge University Press.
The fossils suggest The problem with old bones is that new ones turn up all the time, some of which don’t fit conventional wisdom. For example, a group of archaeologists recently discovered fossil remains of canids that resemble large German shepherds in a Belgian cave that date back 32,000 years. Germonpré, M., Sablin, M. V., Stevens, R. E., Hedges, R. E. M., Hofreiter, M., Stiller, M., et al. (2009). Fossil dogs and wolves from Paleolithic sites in Belgium, the Ukraine, and Russia: Osteometry, ancient DNA and stable isotopes. Journal of Archaeological Science, 36(2), 473–490. For the first evidence of a human-canine bond see Morey, D. F. (1994). The early evolution of the domestic dog. American Scientist, 82, 336–347.
In 1997, an article appeared in the journal Science Vila, C., Savolainen, P., Maldonado, J. E., Amorim, I. R., Rice, J. E., Honeycutt, R. L., et al. (1997). Multiple and ancient origins of the domestic dog. Science, 276, 1687–1689.
Ray Coppinger, a biologist and dog-sled racer Coppinger, R., & Coppinger, L. (2002). Dogs: A new understanding of canine origin, behavior and evolution. Chicago: University of Chicago Press.
even hand-reared wolves Topal, J., et al. (2010). The dog as a model for understanding human social behavior. Advances in the Study of Behavior.
an extraordinary experiment with foxes Trut, L. N. (1999). Early canid domestication: The farm-fox experiment. American Scientist, 87, 160–169.
a geneticist named Dmitri Belyaev Belyaev and his brother supported Mendel’s theory of genetics at a time when Lysenko’s theory of inheritance was official Soviet policy. Belyaev’s brother was sent to a concentration camp where he died. Wade, N. (July 25, 2006). Nice rats, nasty rats: Maybe it’s all in the genes. New York Times.
The foxes’ physiology changed, too Popova, N. K., Voitenko, N. N., Kulikov, A.V., & Avgustinovich, D. F. (1991). Evidence for the involvement of central serotonin in mechanism of domestication of silver foxes. Pharmacology, Biochemistry, and Behavior, 40(4), 751–756. Lindberg, J., Björnerfeldt, S., Saetre, P., Svartberg, K., Seehuus, B., & Bakken, M. (2005). Selection for tameness has changed brain gene expression in silver foxes. Current Biology, 15(22), 915–916. It is less known that at the time he was starting the fox study, Belyaev also began similar experiments on the effects of selection for tameness on other animals including rats. After 70 generations of selective breeding, rats in the tamed strain loved to be petted and played with. Their mean brethren will rip your face off—even if the offspring of mean rats are raised by nice rat moms. Albert, F. W., Shchepina, O., Winter, C., Römpler, H., Teupser, D., & Palme, R. (2008). Phenotypic differences in behavior, physiology and neurochemistry between rats selected for tameness and for defensive aggression toward humans. Hormones and Behavior, 53(3), 413–421.
“chicken-skin music.” I first heard this term from a 1976 Ry Cooder album of the same name.
compared the ability of chimps, wolves, and dogs Hare, B., & Tomasello, M. (2005). Human-like social skills in dogs? Trends in Cognitive Sciences, 9(9), 439–444.
our closest, smartest, and most socially savvy relative Some primatologists would argue that the bonobo, sometimes called the “pygmy chimpanzee,” is just as smart or smarter.
their brains are roughly 25% smaller. Kruska, D. C. T. (2005). On the evolutionary significance of encephalization in some eutherian mammals: Effects of adaptive radiation, domestication, and feralization. Brain, Behavior and Evolution, 65(2), 73–108.
hot debate For an objective overview of thi
s argument see Morrell, V. (2009). Going to the dogs. Science, 325, 1062–1065.
can train wolf pups See Miklósi, A. (2007) and Gácsi, M. Györi, B., Virányi, Z., Kubiny, E., Range, F., Belényi, B. & Miklósi, A. (2009). Explaining dog wolf differences in utilizing human pointing gestures. PLoS ONE, 4(8), e6584.
examples of canine brain power Kaminski, J., Call, J., & Fischer, J. (2004). Word learning in a domestic dog: Evidence for “fast mapping.” Science, 304(5677), 1682–1683. Rossi, A. P., & Ades, C. (2008). A dog at the keyboard: Using arbitrary signs to communicate requests. Animal Cognition, 11(2), 329–338. Range, F., Viranyi, Z., & Huber, L. (2007). Selective imitation in domestic dogs. Current Biology, 17(10), 868–872. Schwab, C., & Huber, L. (2006). Obey or not obey? Dogs (Canis familiaris) behave differently in response to attentional states of their owners. Journal of Comparative Psychology, 120(3), 169–175. Joly-Mascheroni, R., Senju, A., & Shepherd, A. J. (2008). Dogs catch human yawns. Biology Letters, 4, 446–448.
They locate lost kids and rotting cadavers, warn deaf owners For an overview of the many ways that we now use dogs to assist humans, see Zawistowski, S. (2008). Companion animals in society. Clinton Park, NY: Thompson.
believe that their pets have a form of ESP Sheldrake, R., & Smart, P. (2000). Testing a return-anticipating dog. Anthrozoös, 13(4), 203–212.
a way to test what I call the Lassie Get Help hypothesis Macpherson, K., & Roberts, W. A. (2006). Do dogs (Canis familiaris) seek help in an emergency? Journal of Comparative Psychology, 120(2), 113–119.
Adam Miklósi’s group Gácsi, M., McGreevy, P., Kara, E., & Miklósi, A. (2009). Effects of selection for cooperation and attention in dogs. Behavioral and Brain Function, 5, 31.
Researchers at the Center for the Interaction of Animals and Society Hsu, Y., & Serpell, J. A. (2003). Development and validation of a questionnaire for measuring behavior and temperament traits in pet dogs. Journal of the American Veterinary Medical Association, 223(9), 1293–1300.
trainability scores for 1,500 dogs of eleven breeds Serpell, J. A., & Hsu, Y. (2005). Effects of breed, sex, and neuter status on trainability in dogs. Anthrozoös, 18(3), 196–207.
Four and a half million Americans are bitten Sacks, J. J., Kresnow, M., & Houston, B. (1996). Dog bites: How big a problem? Injury Prevention, 2(1), 52–54.
bite strangers, turn on their owners, and pick fights with other dogs Duffy, D. L., Hsu, Y., & Serpell, J. A. (2008). Breed differences in canine aggression. Applied Animal Behaviour Science, 114 (3–4), 441–460.
Pit bulls were once considered a model of courage and loyalty Other breeds have been similarly stigmatized at different times including bloodhounds, German shepherds, Newfoundlands, and Dobermans. Delise, K. (2002). Fatal dog attacks: The stories behind the statistic. Manorville, NY: Anubis Press.
the attacks did not stop This account of the attack is based on a story that appeared in the September 10, 2008, Seattle Times
canine version of racial profiling For the racial profiling argument, see Gladwell, M. (February 6, 2006). Troublemakers: What pit bulls can teach us about profiling. The New Yorker. Best Friends Animal Society is a major proponent of the campaign to rebrand pit bulls “America’s Dog.”
Anthrozoologists are divided on breed bans For an overview of the vicious breed issue, see the point-counterpoint exchange between Alan Beck and Ledy VanKakagage that appeared in the January 2007 Veterinary Forum.
PETA wants pit bulls gone In addition to supporting bans on pit bulls, PETA as well as the Humane Society of the United States took the position that the pit bulls confiscated from Michael Vick’s dogfighting operation be euthanized because animals involved in fighting could not be rehabilitated. However, in April 2009, after considerable discussion, a group of organizations, including the ASPCA and HSUS, agreed to oppose blanket euthanasia of animals confiscated in raids on dogfights.
owners of high-risk dogs Barnes, J. E., Boat, B. W., Putnam, F. W., Dates, H. F., & Mahlman, A. R. (2006). Ownership of high-risk (“vicious”) dogs as a marker for deviant behaviors: Implications for risk assessment. Journal of Interpersonal Violence, 21(12), 1616–1634. A more recent study also found that owners of “vicious breeds” had elevated histories of criminal behavior. Ragatz, L., Fremouw, W., Thomas, T., & McCoy, K. (2009). Vicious dogs: The antisocial behaviors and psychological characteristics of owners. Journal of Forensic Sciences, 54(3), 699–703.
Between 1979 and 1990, rottweilers killed six people Sacks, J. J., Kresnow, M., & Houston, B. (1996).
article on the evolutionary psychology of human-animal relationships Herzog, H. (2002). Darwinism and the study of human-animal interactions. Society and Animals, 10(4), 361–367.
numbers of puppy registrations for each breed for the previous three years Unfortunately, the AKC Web site no longer includes this information. However, annual registration statistics are published in the organization’s magazine, The AKC Gazette.
Their article was about names that people give their babies Hahn, M. W., & Bentley, A. R. (2003). Drift as a mechanism for cultural change: An example from baby names. Proceedings of the Royal Society B: Biological Sciences, 270, 120–123.
the 1,000 most common first names in the United States Check the Baby Name Wizard Web site for a fascinating interactive graph showing how the popularity of baby names rises and falls (www.babynamewizard.com/ voyager#prefix=&ms=true&sw=m&exact=false).
compared power law graphs to a hockey stick Gladwell, M. (February 13, 2006). Million dollar Murray. The New Yorker, pp. 96–107.
“the long tail” Anderson, C. (2008). The long tail: Why the future of business is selling less of more. New York: Hyperion.
This left the other 125 breeds of dogs The AKC typically admits a few new breeds each year. In 2009, three breeds were added, making the total 161.
In 1962 they reached the tipping point It is possible that they reached the tipping point because of the release of a Disney film called Big Red about this time that featured an Irish setter.
a classic case of fashion trickle-down from the rich to the wanna-be-rich Ritvo, H. (1987). The animal estate: The English and other creatures in the Victorian age. Cambridge, MA: Harvard University Press; Grier, K. C. (2006). Pets in America: A history. Chapel Hill: University of North Carolina Press.
devastating critique in the Atlantic Monthly See also Derr, M. (1990). The politics of dogs. Atlantic Monthly, 265(3), 49. See also Derr, M. (2004). Dog’s best friend: Annals of the dog-human relationship. Chicago: University of Chicago Press.
purebred dogs have become a favorite animal model for the study of human diseases For an excellent overview of current research showing how studies of dog genetics have been useful in understanding human diseases, see Ostrander, E. A., & Wayne, R. K. (2005). The canine genome. Genome Research, 15(12), 1706–1716.
trace their ancestry to thirty-one animals Chase, K., Sargan, D., Miller, K., Ostrander, E., & Lark, K. (2006). Understanding the genetics of autoimmune disease: Two loci that regulate late onset Addison’s disease in Portuguese water dogs. International Journal of Immunogenetics, 33(3), 179–184.
as many as 90% of adoptable dogs in some parts of the Northeast Jonsson, P. (June 18, 2008). “Dixie dogs” head north. Christian Science Monitor. Herzog, H. (January 26, 2009) A first dog from down South. Washington Post. Peters, S. L. (April 23, 2009) Doomed dogs get on rescue wagon to other shelters. USAToday.
As a society, we expect women Luke, B. (2007). Brutal: Manhood and the exploitation of animals. Urbana: University of Illinois Press. (p. 15).
Men enjoy hunting and killing Washburn, S. L, & Lancaster, C. S. (1968). The evolution of hunting. In R. B. Lee & I. DeVore (eds.) Man the hunter. Chicago: Aldine Publishing. (p. 299).
interviewed veterinary students This study is reported in Herzog, H. A., Vore, T. L., & New, J. C. (1989). Conversations with veterinary students: Attitudes, ethics, and animals. Anthrozoös, 2, 181–188.
amassing every study For a summary of these findings, see
Herzog, H. A. (2006). Gender differences in human-animal interactions. Anthrozoös, 20(1), 7–21.
equal numbers of men and women own companion animals Pew Research Center (March 7, 2006). Gauging family intimacy: Dogs edge cats (dads trail both). Pew Research Center: A Social Trends Report. This study, which was based on a random sample of 3,000 American adults, found that 56% of men and 57% of women owned a pet. Interestingly, equal numbers of men and women owned dogs (40% versus 39%) and cats (21% versus 24%). Women were slightly more likely than men to consider their pets members of their family. The survey also found that the subjects felt closer to their dogs and cats than they did to their parents.
pay newspapers to publish obituaries Wilson, C., Netting, F., Turner, D., Roth, C., & Olsen (2009) Companion animal obituaries: The “hairy heirs.” Presentation to the International Society for Anthrozoology, Kansas City.
“My pet means more to me than any of my friends.” These items are from the Lexington Attachment to Pets Scale. Johnson, T., Garrity, T., & Stallones, L. (1992). Psychometric evaluation of the Lexington Attachment to Pets Scale (LAPS). Anthrozoös, 5(3), 160–175.
play chase and pull-and-tug with them You might not want to follow our example. Some animal behaviorists believe that playing tug-of-war with dogs gives them the message that it is OK for them to kick your butt and creates long-term dominance issues. The evidence for this view is mixed.
how they played with their dogs Prato-Previde, E., Fallani, G., & Valsecchi, P. (2006). Gender differences in owners interacting with pet dogs: An observational study. Ethology, 112(1), 64–73.
their owners in a veterinary waiting room Mallon, G. (1993). A study of the interactions between men, women, and dogs at the ASPCA in New York City. Anthrozoös, 6, 43–47.
Gail Melson, a developmental psychologist Melson, G. F., & Fogel, A. (1996). Parental perceptions of their children’s involvement with house-hold pets. Anthrozoös, 9, 95–106. For an excellent overview of the roles that animals play in the development of children, see Melson, L. G. (2001). Why the wild things are: Animals in the lives of children. Cambridge, MA: Harvard University Press.