Lecture 4: Hormones & Behavior (NSBED, UU)

Steroids hormones such as estradiol, cortisol and testosterone are important in social emotional behavior. It seems that the estrogen line developed 100 mya earlier than the male androgen line.

The sex steroids testosterone and estradiol are the playmakers.

The social peptides vasopressin (AVP) and oxytocin are the goalgetters.

T underlies the gene expression of AVP (male type line).

E underlies the gene expression of oxytocin (female type line).

Note that female/male type is not female/male (T converts into E).

The social condition in males decides whether testosterone is converted into estradiol.

Testosterone induces social dominance and fearlessness in male and female animals and humans. The effects of oxytocin depend more on species, sex and personality.

Testosterone does not cause aggression by itself. Conditions have to be met for aggression to be provoked.

Low status threat: testosterone upregulates dopamine action in the OFC, which induces decoupling of the OFC and amygdala.

High status threat: in addition to the decoupling, testosterone upregulates AVP expression in the amygdala, this induces hypocoupling. 

Testosterone --> specific social fear

Oxytocin --> generalized anxiety

Oxytocin is thought to be the ‘good hormone’ and T the ‘bad hormone’, but scientific research suggests differently.

Oxytocin makes you love your in-group more, but not your out-group.

Emotion recognition: the orbitofrontal-amygdaloid circuit: for threat faces; the OFC reads-out the amygdala. Testosterone decreased angry faces recognition. Oxytocin increases facial mimicry. Several functional and structural MRI studies show involvement of the inferior frontal gyrus in mind-reading. Testosterone decreases IFG connectivity.

Oxytocin reduces pain, and empathy for pain.

So:

T impairs / OXT improves cognitive empathy and decreased empathic mimicking

OXT decreases empathy for pain / T we show no effect on empathy for pain.

Hypothetical model of the hormones / social brain:

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