Social bonds

Question 1

When did the study of social relationships in animals begin? What started this?

Answer 1

In the 1960s and 70s - Harlow’s monkeys experiments

Question 2

How are social bonds measured in animal behaviour?

Answer 2

Using a Composite social index

Question 3

What does using Composite social index measure?

Answer 3

Compares the frequency of social behaviours for a specific dyad (pair) to the average of the same behaviours in the entire group.

Question 4

What is the composite social index formulae?

Answer 4

(Gij / Gxy + Pij / Pxy) / 2

Question 5

What does a high CSI mean?

Answer 5

stronger bond than average

Question 6

What does a low CSI mean?

Answer 6

weaker bond than average

Question 7

What evidence is there from studying Baboons that CSI can be successfully used to measure social bonds?

Answer 7

Many dyads with low CSI = not particularly friends
Few dyads with relatively high CSI = good friends

Question 8

Provide evidence that chimpanzees have close social bonds

Answer 8

26 of 28 chimpanzees formed at least 1 bond that lasted 5 yeas or more

Question 9

How does closeness between relatives vary in chimpanzees vary?

Answer 9

Longest bond with maternal kin, then paternal kin, then individual close in age

Question 10

Why are longer bonds more equitable in chimpanzees?

Answer 10

• grooming
• meat sharing
• support during conflict

Question 11

Provide evidence for social bonds in dolphin (non-primate) groups - how do they operate?

Answer 11

Dolphins form complex alliances of 2 or 3 usually related males to guard a female

There are different orders of alliances. 2nd order alliances of 4 to 14 males defend or take over females from other alliances.

Bonds made in 1st order alliances can last up to 20 years!

Question 12

Provide evidence for social bonds in Raven (non-primate) groups - how do they operate?

Answer 12

Ravens live in large groups and have very sophisticated social lives - they form coalitions and reconciliations and create interventions of other dyads to disrupt social bonding.

Question 13

What methods have been used to increase our knowledge of animal relationships?

Answer 13

There are few examples for social bonds but there is plenty of evidence for kin and dominance relationships. Playback experiments are used to mimic family in rank reversal experiments.

Question 14

Explain evidence for kin relationships on long-tailed macaques. (Dasser, 1988)

Answer 14

Long-tailed macaques look longer to the picture of an infant seeing a picture of its mother.

Question 15

Explain evidence for kin relationships on rhesus macaques . (Randall et al. 1996)

Answer 15

Rhesus macaques are faster to react to contact calls of their kin and look longer towards the speaker.

Question 16

Explain evidence for kin relationships on rhesus macaques and chimpanzees. (Parr et al. 2010)

Answer 16

Rhesus macaques and chimpanzees can recognise and match parent-offspring pictures in a matching to sample task .

Question 17

What type of kinship is the best predictor of a social bond in baboons? (Silk et al. 2006)

Answer 17

Maternal kinship because they lead to stable relationships over time and are equitable (mutual grooming)

Question 18

Why is maternal kin usually the strongest bond?

Answer 18

it is due to the extensions of infant attraction to its mother. In several animals, female stay in the same group all their lives which leaves plenty of time to form strong bonds

Also kin selection = rB>C

Question 19

Explain Hamilton’s rule formulae rB > C (1964)

Answer 19

r = coefficient of relatedness
B = the fitness benefits of the recipient
C = the fitness cost to the individual performing the act

Question 20

What mechanism is important in social bonds in Baboon groups?

Answer 20

Age difference and rank difference
This relationship is equitable and ensures that the baboons are supported during conflicts

Question 21

Why do baboons create bonds with their peers ?

Answer 21

Dominant individuals sure most of the offspring so infants born roughly at the same time are likely to be paternal half siblings. There is evidence that paternal kin cooperate more than non-kin . They seem to be able to recognise paternal kin.

Question 22

Why do individuals close in rank create social bonds? What is this principle called?

Answer 22

The Similarity principle - animals create binds with those who resemble them the most

Matrilines are females who inherit rank from their mothers so their could be a confound of kinship again

Question 23

Why are humans motivated to cooperate?

Answer 23

More concerned about who has the largest need and therefore doesn’t require equal pay-offs

Question 24

Why are several non-human primates motivated to cooperate?

Answer 24

Non-human primates display a preference for equal rewards but this preference is altered in some species when they cooperate with a friend. (e.g. dogs, chimpanzees).

Question 25

What hormones are involved in the mechanisms of social bonds?

Answer 25

Oxytocin and Vasopressin

Question 26

How are social bonds beneficial for Baboons (Palombit et al. 1987)?

Answer 26

Male and female friendships have a high risk of infanticide

Friendships could reduce stress experienced by mothers

Friendships could increase survival chances of infants (reduce infanticide)

Question 27

How do social bonds help Macaques against predators? (Young et al. 2014)

Answer 27

Macaques give alarm calls when they spot a predator. This leads other macaques to approach and engage in mobbing behaviour.

• Stronger responses were found when hearing alarm calls of friends

Question 28

How does social bonds help Barbary macaques face harsh winters?

Answer 28

Social bonds between male macaques were measured with CSI and stress indicating hormones were also measured. Low temperatures and low social bonds resulted in high stress hormones.

Question 29

How are social bonds beneficial for horses? ( Cameron et al. 2009)

Answer 29

Better social integration was linked to greater reproductive success and reduced stress.

Question 30

What type of communities do Chimpanzees live in ? What happens to the communities?

Answer 30

Fission- fusion communities that range from 20 to 150 animals. Within each community individuals form temporary parties of 2 - 50 animals that fluctuate in size and composition throughout the day.

Question 31

Who do male chimpanzees tend to form friendships with? (Mitani, 2009) How long do these relationships last?

Answer 31

Male chimpanzees form friendships that lasted for many years, sometimes with maternal kin but more often with unrelated individuals.

Question 32

In chimpanzees, what sex form the strongest dyadic associations? (Langergraber et al, 2019)

Answer 32

Although the average index of dyadic party association was higher among males, on average, females had the strongest dyadic associations even though females were rarely close in kin.

Question 33

Who was the first to propose that long-term bonds among adult matrilineal kin arise as an extension of an infant’s interaction with its mother?

Answer 33

Kummer (1971)

Question 34

What is a criticism of using the ‘anthromorphic’ term ‘friendship’?

Answer 34

It claims that animals can anticipate their future social needs. Animals cannot describe what they know. They have a memory of the past but this doesn’t mean they can project into the future.

Question 35

How are friendships adaptive in different ways for males and females?

Answer 35

Among males, allies have superior competitive ability, higher dominance rank and improved reproductive success. Meanwhile, among females individuals with the strongest , most enduring social bonds experience less stress, higher infant survival, and live longer.