Mothers and Others

by Sarah Blaffer Hrdy

  In the course of writing an earlier book, Mother Nature, I recognized how critical alloparental input must have been for child survival in the Pleistocene, but only later did I begin to consider how cooperative breeding evolved in the hominin line and what the implications were for human nature. Invitations to deliver the 2001 Tanner Lectures at the University of Utah and to participate in Barry Hewlett and Michael Lamb’s conference on Hunter Gatherer Childhoods and Eckart Voland and colleagues’ conference on Grandmotherhood provided opportunities to work out my ideas. Then and subsequently, I turned for advice to Sue Carter, who urged me to participate in the 2003 Dahlem Workshop on Attachment and Bonding that she and Lieselotte Ahnert were organizing. This book grew out of the position paper I wrote for the Dahlem volume. Through Sue, I met Karlen Lyons-Ruth, whose thinking about intersubjectivity became a central focus of this book.

  Topics covered here often took me far afield from my own areas of expertise. Fortunately, generous guides took me by the hand. They read and reread particular sections of my draft and, in the case of Marc Hauser, Kristen Hawkes, Polly Wiessner, and Bill Zimmerman provided detailed criticisms of the entire manuscript. Many colleagues answered questions or provided preprints of work in progress. These included Jeanne Altmann, Karen Bales, Kim Bard, Monique Borgerhoff Mulder, Judith Burkart, Jim Chisholm, Janice Chism, Jose Diaz Rossello, Pat Draper, Melissa Emory-Thompson, Linda Fedigan, John Fleagle, Alison Fleming, Jeff French, Pascal Gagneux, Patricia Adair Gowaty, Ray Hames, Sandy Harcourt, Peter Hobson, Dan Hrdy, William Irons, Lynne Isbell, Paula Henry Ivey, David Joffe, Susan Jones, Cheryl Knott, Michael Lamb, Tetsuro Matsuzawa, Courtney Meehan, Jim Moore, James O’Connell, Ryne Palombit, Amy Parish, Noel Rowe, Joan Silk, Meredith Small, Chuck Snowdon, Kelly Stewart, Anne Storey, Frank Sulloway, Bernard Thierry, Ross Thompson, Michael Tomasello, Sarah Turner, Carel van Schaik, Ajit Varki, Bernard von Bothmer, Mary Wister Rawlins, and Katherine Wynne-Edwards.

  I also thank members of the Center for Academic Research and Training in Anthropogeny at the University of California, San Diego; participants of the Parental Brain Conference organized by Robert Bridges, Daniel Smail, and other participants at the workshop on Deep History at the Radcliffe Institute for Advanced Study; and especially Jim Chisholm, Ian Rowley, Eleanor Russell, and Ant and Mary Lou Simpson, my hosts and guides who made it possible for me to watch splendid fairy wrens and some of the other cooperative breeders from Down Under, including those “thuggish” noisy miners.

  From the time this book was no more than a glimmer in my eye, I benefited from the advice of the talented and ever-sympathetic Elizabeth Knoll at Harvard University Press. I also thank Dan Frank and my agent, Peter Ginsberg, for wise counsel and for understanding the special needs of this project. Another old friend, Susan Wallace Boehmer, shepherded the manuscript through its final maturation. The ever-resourceful June-el Piper arranged for photographic permissions, formatted the manuscript, and with the greatest good humor imposed discipline on an awkward and unwieldy process. I cannot thank these supremely gifted literary allomothers enough. I am also grateful to Nancy and Claire DeVore at AnthroPhoto and the wonderful staff at the Peabody Museum’s Photographic Archives.

  On the home front, Gene Miner, office manager of Citrona Farms, offered steadfast technical assistance. Throughout, and as always, my husband, Dan, provided intellectual, emotional, and practical support, remaining the best choice this female ever made. Meanwhile, my co-mother, Guadalupe de la Concha, helped keep our family’s work and lives in balance. With this book I also had a new recruit, my scholar-daughter Sasha, whose pointed critiques of early drafts were among the most valuable I received. And finally, Katrinka and Niko deserve special thanks for keeping me abreast of the way we live now, and for constantly reminding their mother that the “Pleistocene is not the only scene.”

  Index

  Abandonment: of infants, 70–73, 99–100, 103, 120, 228; of elders, 270

  Ache, 151–152, 154–155, 190, 270

  Acorn woodpeckers, 196, 198

  Adaptive behaviors. See Evolution, adaptive behaviors

  Adoption, 146, 228–230, 235–236, 259–260

  Adorableness, 221, 233

  Africa, early hominins from, 16–19, 23, 28, 30, 66, 148–149, 177, 199, 230, 278, 282

  African foragers. See specific groups

  Aggression, 18–21, 26–28, 35, 151, 251, 289

  Agta, 78

  Ai (chimp), 54–55, 57, 236

  AIDS, 118, 288, 292

  Ainsworth, Mary, 118, 124

  Aka, 76–79, 107, 109, 112, 128–130, 132, 134–135, 151, 162–165, 167–168, 171, 245, 268, 286

  Alarm calls, 37–38

  Alley, Thomas, 221

  Alliances, 6, 45–46, 196, 240, 244, 247, 271, 287

  Alloparents, 30–31, 42, 113, 151, 165, 171–172, 233, 238, 258; defined, 22, 177; provisioning by, 59, 79–82, 92, 95–97, 99, 102, 158, 178, 203, 273, 275, 277, 279, 290; breastfeeding by allomothers, 76, 78, 80, 92, 135, 180–181, 226; and cooperative breeding, 80; as critical caregivers, 103–109; supplemental role of, 114–116; infant contact with, 121–123; evolutionary role of, 146, 164, 180, 215, 220; significance of, 177–180; role in food sharing, 180–184; and eusociality, 184–186; and kin selection, 186–190; costliness of not sharing, 190–193; as good helpers, 193–195; benefits of group membership, 195–197; ecological considerations, 197–199; behavioral considerations, 199–203; and sterile castes, 203–207; coercion of, 204–205; competition between, 204, 219; natal attractiveness to, 219–220, 222–224, 226–227; sensitivity of, 220, 267; manufacturing of, 270–272. See also Cousins; Grandmothers; Postreproductive women; Siblings

  Altmann, Jeanne, 158, 218

  Altruism, 4, 7, 28, 36, 96–97, 177; Hamilton’s rule, 186–190; versus costs, 190–193, 197, 254; of aging females, 250–254, 259, 267

  Alvarez, Helen, 244, 246, 249–250, 254

  Amazonia, 85, 153–154, 257

  Ambilocal kin, 244

  Amboseli reserve, 158, 197, 218–219, 253

  American Pet Products Manufacturers Association, 221

  Andaman Islands, 78, 151

  Anderson, Kermyt, 158

  Anomie, 286

  Anthropology, 7, 12, 20, 74, 96, 101, 103, 106–107, 109, 113, 123, 128–129, 140–141, 147, 151, 154, 158, 162–163, 173, 224, 240, 244–245, 249, 255, 257–259, 268, 273, 292; evolutionary, 17, 19, 67; ethnography, 20, 32, 72, 75, 204, 240, 244–245, 249, 268, 282; psychological, 131; paleo-, 148; cultural, 225; physical, 240; demographic, 241–242; medical, 258

  Ants, 185–186, 191–192, 276

  Apostle birds, 179

  Arawak, 27

  Arawete, 154

  Archaeology, 8, 16, 26, 106, 149, 205, 241

  Art, 66, 281–282

  Attachment theory, 82–85, 111, 113–116, 118–119, 124, 126, 128–132, 280, 285, 289–291

  Auk (journal), 177

  Aunts, 79, 108. See also Great aunts

  Australian Aborigines, 133, 217, 245–246, 259, 267

  Australopithecus genus, 8–9, 17, 144, 147, 239, 254, 278

  Autism, 33, 37

  Aye-ayes, 86

  Ayumu (chimp), 54–56

  Babbling, 113, 122–124

  Baboons, 35, 37, 41–42, 45, 51, 69, 84, 86, 90, 158, 160–161, 172, 197, 210, 217–220, 250–251, 253–255, 257

  Bahamas, 27

  Bales, Karen, 172–173

  Bamberger, Joan, 10

  Bamboo lemurs, 87

  Baptista, Luis: The Life of Birds, 201

  Barbados, 150

  Barbary macaques, 88–90, 237

  Bard, Kim, 53–54, 57, 120

  Bare-eared marmosets, 216

  Bare-faced marmosets, 162

  Bari, 154–155, 190

  Barrett, Louise, 218

  Batek, 133

  Beagle (ship), 12

  Bee-eaters, 176, 179

  Bees, 38, 179, 185–187, 271, 276

  Behavior: adaptive, 37, 39–40, 53,
82, 111, 126, 147, 225–226, 231, 240; and cooperative breeding, 199–203

  Behavioral ecology, 9, 32, 105

  Behavioral matching, 58

  Beise, Jan, 262

  Belief systems, 281

  Bellow, Saul, 150

  Beng, 225–227

  Bengali, 263–264

  Bergmuller, Ralph, 192–193

  Betzig, Laura, 105

  Bilocal kin, 244–245

  Biology, 101, 187, 191, 207, 241–242, 293

  Bipedality, 8–9, 11, 17, 28, 65–66, 70, 123, 147, 179, 254–255, 278, 294

  Birds. See individual genera and species

  Birth defects, 57, 70–71

  Birth intervals, 31, 43, 71, 101–102, 247, 250, 262–263, 288

  Black-and-white colobus monkeys, 91, 222–223

  Bliege Bird, Rebecca, 245

  Blindness, 57, 60, 70

  Bloom, Paul, 116

  Blurton Jones, Nick, 76, 106, 255, 268

  Body hair, 69, 72, 123

  Body size, 255, 278

  Bolivia, 154, 257

  Bonobos, 3, 8–11, 17, 21–23, 25, 33–34, 53, 62, 65, 72, 86, 92, 160, 235–236, 240, 249, 272, 275

  Borneo, 222

  Botany, 256–257

  Botswana, 150, 250, 253

  Bowerbirds, 25

  Bowlby, John, 82–84, 111, 113–114, 116, 118–120, 124–126, 133, 285; Attachment, 84–85

  Boyette, Adam, 205

  Brains, 12, 118–119, 197, 220, 273, 276, 280, 282, 286; scans of, 4, 213, 220; neocortex, 6, 40–41, 46, 78, 116; bigger, 9, 18, 28, 30, 45, 65, 67, 116, 137–138, 147, 175–176, 179, 255, 277–278, 281, 284, 292; mirror neurons in, 47–48, 50, 52, 59; and innate responsiveness, 212–215

  Brazil, 10, 87, 94, 104, 122, 150, 154, 172, 227

  Breastfeeding. See Lactation

  Brockway, Raewyn, 42–43

  Brown, Gillian, 96

  Brown hyenas, 181, 188

  Budongo forest, 235

  Burial rites, 65–66

  Burkart, Judith, 96–97

  Burt, Brent, 199

  Bush, George W., 146

  Bushbabies, 86–87, 275

  Bushmen. See Ju/’hoansi

  Byrne, Richard, 45

  Cacioppo, John: Loneliness, 286

  California, 146, 196, 245

  California mice, 162

  Call, Josep, 8

  Callitrichid Research Center, 173

  Caloric requirements, 14, 31, 43, 75, 101, 147, 149, 152, 256

  Calvinism, 262

  Cambridge University, 193, 213

  Canada, 169–170, 259, 263

  Canela, 154–155

  Cant, Michael, 207

  Capuchin monkeys, 86, 92

  Caregivers. See Alloparents; Fathers; Mothers; Postreproductive women

  Caring, 2, 6–7, 22, 29, 36, 42, 164, 180; essential to survival, 11–16, 18–21; shared, 25, 75, 85, 91–102, 105, 113, 122, 124, 131, 176, 184, 199, 202, 204, 207, 228, 230–231, 233, 238–240, 275, 277, 279–280, 294; among primates, 87–92; critical importance of alloparents, 103–105

  Catarrhine monkeys, 84

  Catfish, 200–201

  Cave paintings, 66, 281

  Cebus monkeys, 92, 228

  Centre of the Study of Emotion, 53

  Chacon, Richard, 166

  Chagnon, Napoleon, 154

  Characin fish, 293

  Chastity, female, 265, 287

  Chauvet cave, 281

  Childbirth, delayed, 103, 288

  Children, 34, 36, 103, 140, 286; food gathering by, 10; mortality of, 16, 67, 105, 259; post-weaning, 31, 183, 275; sex roles of, 42; sense of self, 59; prereproductive, 75, 124, 217–219, 269, 274; caring by, 105, 107–108; intuitive/language skills of, 135–136, 283; and loss of parent(s), 150–151, 166; and trust, 291–292. See also Infants

  Child psychology, 111, 285

  Chimeric paternity, 155–157

  Chimpanzees, 3, 9, 22, 38, 65, 84, 136, 148, 204, 254, 294; homicide by, 4, 19, 21, 46; use of tools by, 8; and cooperation, 10, 35–36, 46, 231, 279; lineage of, 17, 23, 29–31, 66, 72, 86, 100, 123, 278, 280; and giving/sharing, 21, 25, 35, 96–97, 137; and food, 25, 34–36, 45, 256, 275; response to strangers, 27, 122, 235; behavior of, 33–37; empathy in, 34–35, 53, 56, 61; mothers, 43–44, 53–56, 68–70, 91, 101, 112–114, 120, 138, 216, 234–235; and status, 45; infanticide by, 46, 233–235; and eye contact, 51–52, 56–57; infants, 53–59, 61–62, 68–70, 80, 101, 112, 114, 120–123, 138, 225, 234–235; imitation by, 58–59; fathers, 160; female migration, 197, 239, 271; adoption among, 236; breeding system of, 243, 249, 267, 271; self-medicating by, 257

  China, 18, 153, 205

  Choughs, 179, 191, 195

  Christianity, 15, 146, 157, 262

  Chuckchee, 12

  Cichlid fish, 176, 192–193

  Climate fluctuations, 5, 19, 230

  Clinical psychology, 48

  Clutton-Brock, Tim, 193–194

  Cockburn, Andrew, 189

  Code of Hammurabi, 206

  Coercion of allomothers, 204–205

  Cognitive abilities, 2, 8–9, 28–29, 39, 47, 50, 54–56, 58, 103–105, 116, 131, 136, 172, 231, 279–280, 292

  Cognitive psychology, 2, 32, 138

  Colobus monkeys, 3, 46, 86, 90–91, 102, 222–223

  Columbus, Christopher, 27

  Comfort suckling, 178

  Commitment: maternal, 104, 112–114, 118–120, 139, 283–286, 290; paternal, 150–153, 161–162, 166–167, 174

  Co-mothers, 204, 238

  Comparative infant development, 32, 53

  Comparative psychology, 8, 52

  Compassion, 4–5, 28, 37, 132, 293

  Competition, 7, 11, 19, 26, 31, 34, 45, 52, 231, 270–271, 277, 279; between infants, 5, 160, 220, 222; between mating males, 5; between mothers, 5, 204–205, 214, 246, 267, 287; between groups, 19–21, 27, 30, 37, 288; social, 46, 62; between alloparents, 204, 219; sperm, 248–249

  Congo, 25

  Continuous care and contact, 68–70, 72, 74, 83–85, 91, 113–114, 118, 123–124

  Cook, James, 27

  Coontz, Stephanie, 103

  Cooperation, 4–5, 7, 9, 22, 28, 34, 175, 187, 293; evolutionary basis of, 6, 11–12, 52, 65–67, 283; by chimpanzees, 10, 35–36, 46, 231, 279; within-group, 19–20, 30–31, 230–231; and mind reading, 29, 37, 279–280, 286; in feeding young, 95–96

  Cooperative breeding, 30, 32, 105, 212, 224, 264, 272, 275; defined, 30; evolution of, 31, 107, 124, 156, 164, 167, 176, 197–199, 230–231, 245, 276–280; role of alloparents, 80; in marmosets/tamarins, 92–101, 122, 156, 173–174; and attachment theory, 113, 285; effect on males, 168–169, 172, 174; early studies of, 177–180; critical importance of sharing food, 180–184; and eusociality, 184–186; Hamilton’s rule, 186–190; costliness of not caring, 190–193; need for good help, 193–195; benefits of group membership, 195–197; and ecology, 197–199; and behavior, 199–203; and sterile castes, 203–207; possible candidates for, 227–231; flexible matings in, 249. See also Provisioning; Shared care

  Cormorants, 25

  Cortisol, 71, 170, 261

  Costly young, 21, 100–102, 146–148, 151, 153, 162, 180, 250, 273

  Cost/benefit components of altruism, 190–193, 197, 254

  Cotton-top tamarins, 100

  Cousins, 26, 79, 90, 112, 134, 245, 265, 269

  Couvade symptoms, 98, 170

  Co-wives, 246

  Coyotes, 181

  Cree, 133

  Crittenden, Alyssa, 165, 204–205

  Crocodiles, 39

  Crows, 198

  Crying, 42, 82–83, 170–171

  Cuckoos, 200–201, 228

  Cuiva, 152

  Cultural anthropology, 225

  Cultural evolution, 281–282

  Culture, 66–67, 132, 147, 173, 227

  Curiosity, 28, 115

  Darwin, Charles, 11–12, 18, 24, 33, 53, 82, 84, 157, 167, 177, 179, 200, 209, 211, 231, 268; The Descent of Man, 147; On the Origi
n of Species, 32

  Daycare, 102, 124–126, 130–132, 288

  Deak, Viktor, 284

  Deception, 45–46, 137

  Decrepitude, 241, 270

  Demographic anthropology, 241–242

  Demographics, 101–102, 166, 206, 241–242, 246, 259, 261, 267–269, 289

  Dennis, Wayne, 60

  Detachment, 118

  Developmental psychology, 48, 51, 82–83, 113–114, 281, 285, 289

  DeVore, Irven, 44

  De Waal, Frans, 34, 279

  Dholes, 181

  Dingos, 194

  Dinosaurs, 39

  Disease, 19, 31, 118, 226, 248, 286, 288, 292–293

  Disorganized attachment, 289–290

  Divorce, 150, 152, 165

  Djungarian hamsters, 216

  Dmanisi site, 18, 284

  DNA, 9, 12–13, 33, 93, 157–158, 162, 189, 203, 243, 247–248, 280. See also Genetics

  Dogs: domesticated, 39, 59, 248, 283; wild, 80, 93, 176, 179, 181–183, 194, 203

  Dollo’s Law, 293

  Dopamine, 213

  Double, Michael, 189

  Dozier, Mary, 290

  Draper, Patricia, 166

  Dunnocks, 188–189

  Durkheim, Emile, 286

  Dusky leaf monkeys, 91, 222

  Dwarf hamsters, 162

  Dwarf lemurs, 86–87

  Dwarf mongooses, 93

  Earl, Timothy, 151

  Earwigs, 210–211

  Ebony langurs, 222

  Ecological constraints hypothesis, 190

  Ecology, 9, 28, 32, 105, 148–149, 206, 241–242, 260, 278, 282; and cooperative breeding, 197–199

  Economics, 5–7

  Efe, 76–80, 107, 168, 205, 256, 265, 268, 286

  Eibl-Eibesfeldt, Irenäus, 24, 26, 50, 81, 139, 141, 154

  Eipo, 24, 72, 217

  Elephants, 178, 181, 196

  Eliot, George, 120

  Elowson, Margaret, 122–123

  Embarrassment, 117, 133, 282–283