PSYC 311 1st EditionLecture 23Current LectureApril 23 - Evolution of parental favoritism o General rule – nurturance provided to offspring with best probability of surviving to reproduce  Usually first to hatch  Biggest chick o Siblicide – one sibling attacks the other – worse when resources are scarce  Parents of some species do nothing, others intervene and prevent siblicide  Some species of birds have more androgens (associated with aggression) to first egg laid  Parents may favor fitness - Size, vigor, pigment pattern Evolution of Social Behavior (powerpoint 2)A. Advantages a. Predators (D+D+D)i. Dilution ii. Defense: mobbing, stampeding, selfish herd iii. Detection: more ears/eyes/noses to detect presence of predator 1. Meerkat, baboon, guinea hens, etc (warning cries) b. Foraging efficiency – finding food, food hoots i. Size of prey – group attack ii. Protection of kill/food resources, group defense of territoriesc. Care of young – meerkats, wild dogs, hyenas, wolves d. Other advantages i. Thermoregulation – huddling together when it’s cold (rotation)ii. Locomotor efficiency – geese “v” pattern iii. Social stimulation, grooming, synchronization of mating, migration, etc. 1. Cooperative insecticide behavior – removing parasites B. Disadvantages a. Competition with conspecifics for mates, food, shelter, dominance b. Increased problems with health, stress, parasites i. Insecticide treated nests foster bigger, healthier chicks ii. Stress increases vulnerability to diseases iii. Calhoun – population density and social pathology 1. Rats showing abnormal behaviora. Mother rats build nests in safe places away from others b. Too many other smells for her to find her pups again c. Rape, incest, homosexuality2. Olfactory and pheromonal cues associated with regulation of mating and social behaviors  abnormal sexual, social and reproductive behaviors noted 3. Behavioral sinks – areas where animals clustered in great mass a. Around feeding, watering areas c. Energy spent on attending to demands of dominance hierarchy i. May decrease time/energy available for reproducing genes d. Increased conspecific aggression – increased aggression by other adults to offspring and aggressive reproductive interference i. Infanticide – passion (infanticidal chimp mother, described by Goodall) ii. Social animals have evolved signs of submissiveness and other behaviors designed to predict/end attack e. Increased predator pressure – predators attracted to high density areasf. Inappropriate young – loss of ability to recognize offspring g. Increased probability of inbreedingC. Cooperative Behavior a. Related vs. unrelated vs. across species b. Helping behavior – elephants and chimps c. Mutualism – both cooperate, both benefit i. Both have reproductive interaction 1. Male nomad lions2. Manakin courtship: alpha vs. beta males ii. Inter-species mutualism 1. Ants and butterflies – ants provide protection, butterflies provide nectar d. Reciprocal altruism – animals that are “helped” return the favor later i. Sentry behavior (meerkats)ii. Grooming: social comfort, bonding, snacks of parasites 1. Social grooming (allogrooming) – decreases tension and aggression; association with endorphins and hormone release (oxytocin) 2. May be exchanged for protection (bats)iii. Loafing – they receive, but never give 1. Cheaters – loaf off of the altruistic e. Kin selection – cooperation increases survival probability of kin (share genes) i. Help those related to you (sheep)f. Group selection – species that cooperate have increased chance of survival, over those that do not cooperate i. Dyadic – two individuals cooperate ii. Polyadic – more than 2 cooperate iii. Coalitions – two individuals/groups against other individual/group 1. Alliances – long lasting coalitions g. Altruism – helpful donor permanently loses reproductive opportunity by placing itself at risk to indirectly increase reproductive fitness of othersi. WD Hamilton – Hamilton’s Rule ii. JBS Haldaneiii. Indirect vs. direct selection iv. Inclusive fitness h. Eusocial behavior – species that include non-reproductive working castes i. Haploidipoidy – species employing eusocial system 1. Haploid – only have one copy of each gene (non-fertilized egg  male drone)2. Diploid – having 2 copies of each gene in one’s genotype(fert. Egg worker females)ii. Ex: naked mole rats Play Behavior - Play behavior – appears in more advanced, social animals o Motor activity, appears purposeless, features motor patterns from other contexts - Typeso Object play – pushing, throwing, manipulating an inanimate object  Often preceded by object exploration – practice and information for what is needed later in life o Locomotor play – physical activity that may be practice for behaviors required later in life  Important for exploration – learning environment (exercise) o Social play – play activities with other  Essential for foraging bonds and development of social behaviors (dominance systems, coalitions, friendships)- Contact vs. non-contact (see