A new researched showed that two parts of brain are in control of making safe and risky investment decisions.
In a group of adult volunteers who were asked to make investment decisions between two stocks and a bond by pressing a button researcher scanned the participants' brains and learned the results of the choices. The results showed that brain activity in certain specific regions tended to activate before participants made risk-seeking investment mistakes while other specific brain areas were activated before the participants made conservative, risk-averse investment mistakes.
It seems that these areas of the brain are rather deep and not associated with math and taxes. They're more associated with emotions or how people feel before they're about to do something. So, it is anticipatory emotions that may have some role in decision-making process.
This is probably why most casinos surround their guests with reward cues, such as inexpensive food, free liquor, surprise gifts, and potential jackpot prizes.