Why people do the same damn thingg(denial,self decieve ect.) even if it leads to thier own demise? Here is a likely culprit..as any ..
SUNK COSTS
To understand the notion of sunk costs, consider that when one pursues a goal and the pursuit is frustrated as one gradually comes to learn that one cannot really reach the goal, there are useless costs that already have been incurred along the way in what now looks to be a futile pursuit.
Rather than abandoning the pursuit of a goal that can now be seen to be impossible to attain, human beings are typically resistant to giving up. This amounts to irrational persistence. We human beings seem to have much difficulty accepting that all costs already incurred in a futile pursuit are sunk, or, as is also said, are stranded costs. These sunk or stranded costs have taken us nowhere near our goal and almost certainly never will; so we must conclude that our past effort and other costs can serve only to teach us we have been on a dead-end pursuit. But we may not want to come to this conclusion no matter how compelling the evidence.
The lost, stranded, or sunk costs in pursuing a goal that now comes into focus as practically impossible to attain are a powerful image that can irrationally sustain still more futile motivation to persist in pursuit of a lost cause. "I've put all this effort into this project, so I'm not going to leave it behind now no matter what!" can be either the rational voice of reasoned optimism or the irrational voice of someone lost in the irrational psychology of being unable to yet accept that one's costs are sunk and will continue to sink more if put into the same old futile pursuit.
In this state of resistance we are irrationally persistent and then are likely to incur still more sunk costs to pursue what is surely a lost cause!2 The ubiquity and power of the psychology of the irrationality of futile persistence when having to confront the harsh reality of sunk costs should not be underestimated. The irrational human persistence in pursuit of lost causes for which one has already incurred many stranded costs is powerful enough, but it is made even more powerful whenever the goal that is unattainable is a "maintenance goal" as opposed to merely an "acquisitive goal." Accordingly, it is important to know the difference between these two kinds of goals.
TWO KINDS OF GOALS
A maintenance goal exists when the goal we are seeking is anticipated to be almost within reach such that we can also easily anticipate our satisfaction in its achievement. We anticipate so confidently, that is, that we are in an "as if" state of mind in which we feel as if our satisfaction of goal attainment is nearly upon us. So confident do we feel that we actually dwell more and more on the enjoyment of imagining having already attained the goal. This is tantamount to regarding our pursuit of the goal "as if" it were completed, as if, in a sense, the goal has already been achieved and our continuing pursuit of it is merely to maintain our enjoyment in contemplating it. Maintenance goals are imagined so confidently as just within reach and as already enjoyed in anticipation that pursuing them feels like--but is not--the same thing as merely maintaining the goal. Acquisitive goals, on the other hand, are not so confidently pursued and thus are not felt to be enjoyed or enjoyable until they are finally attained in actuality. If one has to face the reality of sunk costs in pursuit of an acquisitive goal, the irrationality and suffering from disappointment is not so severe as when having to face the sunk cost of pursuing a maintenance goal. For in the case of frustration of a maintenance goal, one's disappointment is not simply that of having failed to find a sought--after satisfaction; instead one also experiences the frustration as something more--as an actual loss. It is "as if" something were lost since one perceives a frustrated maintenance goal "as if" it has already been attained and then lost--as if one were cheated or robbed of a cherished possession.
http://primal-page.com/duffy1.htm