Decision making is a multi-faceted subject. It goes beyond just deciding yes or no. As the resources below will show you, there are a number of ways to make decisions optimally.
Why do people do what they do? Behavioral economics seeks to combine economic theory and human behavior to answer why.
Daniel Kahneman is a giant in the field. Start with his work:
We often think that we know what’s best and it would be nice if we could just get people to see it our way. You can use subtle cues called “nudges” to push people towards what you want them to do.
A niche area of decision theory is optimal stopping. Optimal stopping is meant to calculate the best point at which to stop seeking new choices and make a decision amongst your existing options. This is one of the few areas of mathematics where laypeople can understand the immediate significance of the concept.
No one is perfectly rational. By recognizing your cognitive biases, you can counteract the hidden impairments to making good decisions.