Living beings, and of course humans, decide primarily based on their feelings.
The reason for this lies in the primordial structures because; at the very beginning of life there was no cognitive decision, only sensory information recordings, which later, depending on the organism, showed up as feelings.
In the course of evolution, feelings remained superior to decisions based on the respective goals.
In mammals, and especially in humans, the frontal lobe (lobus frontalis) developed and developed more and more - because he was successful with it. This took on more and more volume over time. In humans, it now makes up more than 30% of the cerebral cortex.
But since the brain is imbued with stored emotions, these have a very great influence and often weaken or suppress - through the midpoint-mechanics - the reasoning of the mind.
This can be seen very well, for example, in the feeling (belief) of free will or that the person makes conscious decisions (and not the brain).
Without a doubt, feelings have a central, healthy function for humans.
But: without question, they don't always make the right decision.
Restricted emotional life (often genetically determined) can bring considerable disadvantages for humans, similar to the consequences of frontal lobe damage.