Lecture 19: Human and animal Flashcards
Describe the history of social bonds
The first studies began in the 60s and 70s. Then Hinde did his famous study in 1979 about social development and attachment. He looked into the characterisation of mothers and their offspring after brief separation. The behavioural consequences depends on the relationship before separation, the separation led to long-term behavioural changes and the social context in which the separation occurs is important.
Define social bonds
A long term enduring social relationship between the same or opposite sex, it’s mutual beneficial. There must be close proximity and a frequent change of affiliative behaviour, like grooming.
How do you measure a social bonds?
Via the composite social index (CSI) developed by Sapolsky 1997. It compares the frequency of social behaviours for a specific dyad with the average frequency of the same behaviours in the whole group. It’s worked out via: Gij / Gxy + Pij / Pxy / 2. G= frequency of grooming between individuals x and y. Gxy= the frequency of grooming in group x during year y. High CSI means there is a stronger bond than average.
Describe a piece of research that supports animals having social bonds
Part 1: Baboons
Silk 2006 collected data for more than 30 years and found that many dyads had a low CSI but some had particularly high CSIs meaning they were close friends.
Describe a piece of research that supports animals having social bonds
Part 2: Chimps
Mitani 2009 found that 26 out of 28 chimps formed at least 1 bond that lasted 5 years minimum. Strongest bonds were between maternal kin, then paternal kin, then those that are closest of age. This mainly occurs with males as they stay in the same group for their whole life, unlike females. Longer bonds were associated with grooming, meat sharing and support during conflicts, aka altruism. This was partially replicated with different groups.
Describe a piece of research that supports animals having social bonds
Part 3: Non-primates
Connor 2007 found that 2 or 3 male dolphins form complex alliances in order to guard a female. Then there’s second order alliances which involve 4 to 14 males that defend or take females from other alliances. The males are usually related and a first order alliance usually lasts for up to 20 years. They have complex bonding and reconciliation after conflicts.
Do animals know about their social bonds?
There is few examples for social bonds but there are examples of kin or dominance relationships.
Bergman 2003 did a playback experiment where he mimicked family rank reversal. He looked at relationships between family a (highest rank), family b and family c. He found that there was a significant difference in looking at members between families (longer) compared to within families.
Dasser 1988 found that long tailed macaques looked at a picture for longer if an infant was shown to them after they were shown a picture of the mother. Macaques also respond to calls faster if it was their kin. They can also match pictures of parents and their offspring.
What are the mechanisms for social bonds?
Part 1: Baboons
Silk 2006, He found that maternal kinship was the best predictor for social bonds as they had stable relationships that were equitable. This is because of an infant’s attraction to its mother as its in close proximity to her for the majority of its life. Also it’s because of kin selection as its beneficial so support genetically related individuals; rB > C. Age difference and rank difference also plays a role. Dominant individuals produce more offspring and the offspring are likely to be paternal half-siblings who cooperate more and they can recognise their father. The animals establish bonds with individuals that they are most similar to, e.g. age, genetics etc. Daughters inherit ranks so there is kinship here, they’re matrilines.
How do social bonds benefit participants?
We have a motivation to cooperate, for example friends will help out those who are in largest need and they don’t require an equal pay-off. Non-human primates prefer equal rewards however this alters with cooperation in friendship. This is found with dogs and chimpanzees. It’s also good for reciprocal altruism, individuals calculate this and keep track of how much is given versus received. However, this is cognitively demanding as they have to keep track of interactions, postpone immediate reward and plan for future reward. There is also symmetry based altruism which is when individuals are altruistic to others of a similar age, kin or mutual association. This is much simpler, vampire bats do this. Or animals could have attitudinal reciprocity which is short term, grooming in the morning and being groomed in the afternoon, this is simple as well. Finally there is emotionally mediated reciprocity which is a decision based approach on the quality of the friendship at the time but this is hard to research.
Describe the neural and hormonal mechanisms for social bonds
Oxytocin and vasopressin play a role in the formation and maintenance of social bonds. They are highly conserved between species and they affect human behaviour, for example oxytocin makes people trust strangers more.
Describe the function of social bonds in baboons
Palombit in 1997 found that baboons have male-female friendships as it reduces stress after infanticide and it reduces the chance of infanticide occurring. They have female-female friendships. The more secure and stronger the bond is, the less peripheral and less vulnerable to predation the baboon is, the better they’re shielded from social conflicts, allowing them to feed more and the lower stress levels they have, measured through glucocorticoid levels.
Describe the function of social bonds in macaques
Micheletta 2012 found that there is a stronger response to an alarm call if its produced by a friend meaning they’re more likely approach and engage in mobbing behaviour.
Describe the function of social bonds in horses
Cameron 2009 found that social integration linked to better reproductive success and reduced stress.
