Pre-Disposed

http://www.livescience.com/39299-downers-predisposed-dislike.html

"Nah," "eh," "no" and "ugh": These are the familiar sounds of people who don't seem to like much and conjure negative quips for just about anything. While people with more positive dispositions may try to shake enthusiasm unto these downers, new research helps to explain why this often doesn't work.

That certain people like more things than others may seem obvious, but, until now, nobody has ever tested whether such dispositions operate as distinct personality traits, separate from other traits such as optimism/pessimism or extroversion/introversion. A team of researchers from the University of Illinois at Urbana-Champaign and the University of Pennsylvania have now conducted the first quantitative analysis of dispositional attitude, finding that it is, in fact, distinct from these other traits.

"Optimists tend to have generalized beliefs usually about the future, such as 'Things are going to turn out well,'" said Justin Hepler, a professor of psychology at the University of Illinois at Urbana-Champaign and an author on the study. "We were interested in whether people liked or disliked things, in general, and had people report their attitude about different things."

http://www.livescience.com/8343-personality-predicted-size-brain-regions.html

In a social situation, it's easy to tell the difference between a wallflower and the life of the party, but a new study suggests we can also spot differences in their brains.

The results show the size of certain brain regions is related to people's personalities. For instance, highly altruistic people had a bigger posterior cingulated cortex, a brain region thought to be involved in the understanding of others' beliefs. Bigger regions are assumed to be more powerful. [Top 10 Mysteries of the Mind]