Insight: Our intuition (shown through language before the existence of scientific support) tells us that the temperature of a persons head is inversely proportional to his state of rational thought. Emotional thinking increases the temperature of the head. Maybe the loss of hair through aging has developed to indicate the individual's capability to contain his emotions and produce logical behavior patterns.
Again, I've lost my references as to the science I read (what a great blog I have) but I've still got to put the idea out there.
As to the already understood social knowledge:
- let cooler heads prevail
- heat of the moment
- cool confidence
When human's are younger, emotional thinking may be necessary to spur an individual into action. As we age, we have become familiarized with many more situations, thus we behave accordingly: we are presented with a scenario, we react with a learned response.