Mothering and childcare

Question 1

Hinde & Milligan (2011) milk

Answer 1

Variation in milk is due to maternal condition (twins born to small mum grow slower), nutrition and environment
Close mother-infant contact = more dilute milk. Bush babies ‘park’ their offspring, have more concentrated milk
Dilute milks are associated with slower infant growth, protracted lactation and long period of infancy.
Accelerated growth requires richer milk to sustain their rapid rate of development.
Brain size and milk: metabolically expensive neural tissue requires nutritionally dense, high quality foods. Human infants require 3-4 times the amount of glucose than adults. Proportion of energy from sugar, which is used by the brain, may be correlated with mass.

Question 2

Hooded seals

Answer 2

Lactate almost continuously for 4 days before weaning, must transfer 7kg of fat each day. Give birth and lactate on unstable ice sheets, pup wouldn’t survive without substantial body fat reserves. This also sustains them while they develop swimming and hunting abilities

Question 3

Humans (H&M 01)

Answer 3

Humans: US adolescent mothers produced lower volume than adults. Chinese young mums in urban areas were better educated, better diets and milk higher in fat and protein. Reducing caloric intake for 1 week decreased milk volume by 15%. Increasing made no difference to the composition, maximum is physiologically determined in pregnancy

Question 4

Lummaa (1998) why cry?

Answer 4

Capacity for crying demands extra energy, increases energy expenditure 13% in new-borns. So, it’s costly and could reduce growth rates. Honest signal? Should only be expressed if the benefits exceed the costs.

Question 5

Colic syndrome

Answer 5

A medical cause for colic is found only rarely; instead of regarding the colicky behaviour of human neonates as a medical syndrome, it should be regarded as continuous with normal crying, and a predictable consequence of care giving practises in western societies (separation of baby from mum)

Question 6

Lummaa (1998) 4 hypotheses

Answer 6

Separation distress
Blackmailing
Anti-infanticide
‘Super-child’

Question 7

Hunziker (1986)

Answer 7

Increasing mother-infant contact between 4-12 weeks of age = 43% decrease in daily duration of crying. Frequency didn’t change, which suggests extended crying bouts are a result of western care practises

Question 8

African !Kung San mothers

Answer 8

Carry their infants constantly and feed them more frequently. More likely to respond rapidly to crying

Question 9

Daly & Wilson (1994) difference between step-parent and genetic parent homicides

Answer 9

We expect an increased risk from S-F when we consider how natural selection is expected to shape evolved mechanisms of parent psychology. Animal males act in the ‘expected’ way
Canadian and UK homicide databases from 70s-90s
Much greater risk of S-F homicide. A lot less likely to have committed suicide in conjunction with killing, which would suggest a ‘rescue’ motivation
Gen-F more likely to shoot/suffocate, S-F more likely to hit/kick or beat
Gen more likely to kill out of perceived necessity
S-F more likely to be motivated by hostile resentment of the victim (wouldn’t stop crying..)