Science writer David Weiner discussed neuroscience, psychology, and positive thinking, and also offered analysis of the psychopathic mind. Psychopaths, he explained, don't feel guilt or empathyâ€"biologically those circuits aren't there, and thus they can't be "fixed." He estimated that 1% of the population is psychopathic but that the threat of prison and prosecution deters most of them from committing crimes. He differentiated them from sociopaths, who arrive at a similar mentality from cultural rather biological influences.

The brain is hardwired to deal with such issues as territoriality, power and attachment. (For your individual ranking on power status, see this Quiz from Weiner's site.) He noted that people can be sabotaged by their brain's functioning, such as from "false alarm" fears that originate in the amygdala. But by working through fear, and keeping a positive attitude these obstacles can be overcome, he added.

Healthy serotonin levels are associated with confidence and optimism, said Weiner. Beyond that, he shared that one can work towards a positive attitude by practicing mental exercises such as affirmations as well as through "journaling." The practice of journaling is especially helpful to do after one feels slighted or defeated, and involves writing your response to four columns: 1) what happened? 2) how do you feel? 3) how should you feel? and, 4) how do you feel now?

Water on Enceladus

First half hour guest, NASA scientist David Morrison reported on Cassini's water discovery on Enceladus, a small moon of Saturn. Evidence of geysers erupting from underground pools raise the possibility that life might exist in some form there, as liquid water is the one requirement we know that is needed for life, he said.