Scientific studies in the fields of psychology and biology tell us that we are hardwired, most likely by evolution, to react impulsively and in biased fashion to the world around us.
Financial market professionals are well aware of our susceptibilities, and they purposely use them against us. Some sales agents impose time pressure and insist that we make a quick decision or somehow lose out. They hope we will make an impulsive decision that benefits them, instead of a reasoned one that benefits us.
Take your time when making decisions. Don’t allow others to drag you into premature ones.
Awareness is an important factor. Being aware of our psychological susceptibilities puts us on alert and allows us to employ healthy skepticism as we sift through information.
Discussions with a spouse, partner, or friend provide another line of defense and reduce the decision-making burden. The perspectives of people we trust help us to stay grounded.
Finally, when it comes to decision making we sometimes forget that a decision has not been made until we consciously take some action. Resolving to do something in your mind, but not actually doing it is not decision-making.
 We tend to divide evidence of irrationality into separate biology and psychology categories, but in reality biology dictates psychology, so the distinction is not relevant.