Health Risks in Relationships
relationship dissolution are associated with significant health risks
Paternity Uncertainty
lack of certainty in whether the father has genetic bonds to the child
Unrelated Measurements of Paternity
- outside people aren’t accurate at determining paternity
- different resemblances to child across their age course, boys more like their fathers during childhood, girls persist across age
Related Measurements of Paternity
- mothers ascribe more resemblance to the father to their newborns
- maternal facial perception is biased towards father, possibly to reassure father paternity
Cinderella Effect
tendency for poor treatment among step/non-biological parents
Bruce Effect
the termination of pregnancies after exposure to unfamiliar males
- Gelada (baboon) terminate 80% of pregnancies in weeks after dominant male is replaced
- adaptive for females to abort fetus instead of waiting for birth where infanticide would occur
Filicide
killing of a child by a parent or parent-equivalent
- average 20 a year in Australia
- risk factors include criminal history, domestic violence, parents with mental illness or substance abuse
Testosterone and Fatherhood
- men in relationships have lower testosterone
- age-related decrease in testosterone
- relationship status
Testes size
- negatively correlated with paternal investment
- higher testosterone and bigger testes demonstrate lower caregiving
Dopamine and Pair Bonding
- neurons in the area that receive dopamine input have specialised receptors
- either D1 or D2
- In Nucleus Accumbens, D2 activation facilitates bonding, D1 activation opposes it
Step 1: Bonding
- dopamine binds to D2 in nucleus accumbens
Step 2: Brain Change
- D1 levels increase in nucleus accumbens
Step 3: Exclusivity
- increased D1 levels prevent formation of new bonds, cause aggression towards strange females
Corticotrophin-Releasing Factor (CRF) and Addiction
- starting point of stress response
- receptors expressed in stress-sensitive areas of the brain
- increased by drug withdrawal symptoms, stressors
- influenced by emotional responses
- input of CRF suppresses the depression/ stress effects
Love withdrawal in Voles
seperation from a female partner causes males to show depressive-like behaviours
- compared siblings to partners
females find bonds with family and friends of the same sex as reason to mourn
Love and Addiction
- use similar neural mechanisms
- secure social bonds counteract drug addiction
- dopamine is important for the initiation of bonding
- CRF mediated stress is responsible for motivation to seek out drugs or partner
Promiscuity of Fairy Wrens
- their genetic health is increased by having more eggs fertilised by different males = benefit of variety
Advantage of Alpha Male in Chimpanzees
- alpha males tend to father more children than non-alphas
- although females have more access to resources the more they mate
Motivation induced by CRF to maintain addiction
negative reinforcement acts as a greater motivation for substance dependence as it grows in intensity to maintain an equilibrium
