Four Cognitive Biases can be overcome in part by powering up some multiple selves, including deformation professionelle, hyperbolic discounting, and  myside bias (to include  confirmation bias and disconfirmation bias).

Our tendency to look at an issue  only according to the conventions of our own profession can be countered by intentionally switching to another self, for example, from one’s Inner Economist to Mr. Dad.

Our Hyperbolic Discounting Bias  explains aspects of addiction, not saving for retirement, borrowing on credit cards, buying health club memberships (vs. using them) and procrastination. We may be able to counter it by unleashing our long-term (responsible) self against our short-term (impulsive) self  — confronting Dr. Jekyll with Mr. Hyde, or setting The Very Reverend Doctor SuperEgo against Master-Monster Id (as in this Dual-self Model of Impulse Control).

Our Myside Bias makes us actively search for only confirmatory evidence for our existing beliefs, and should we happen to stumble across disconfirming evidence,  to scrutinize it intensively for shortcomings. It’s as if we had fallen in love with our own belief, thus admitting our ‘   …intellectual affections to the place that should be  dominated by impartial intellectual rectitude. "

But suppose we free the multiple Lovers within our self, so that each of Us can caress his favorite one of a whole bevy of Multiple Working Hypotheses,  each of whom one of us loves the best of all when we are  with them?  Then  for our whole Pride of Lovers within,  ‘Having thus neutralized the partialities of [our] emotional nature … proceeds with a certain natural and unforced erectness of mental attitude to the investigation…’

Finally, ‘Personality’ is arguably situation dependent ; indeed many of us already know we can switch selves simply by putting ourselves in a different situation (in fantasy seems to work as well as in reality). Is this the accurate part of our trait ascription/ actor-observer bias?  And is the wrong part our denial of the same mutability to others?  My answer to that question starts with the question: Which do I know the best, myself or others?  And one  good  answer seems to be: Do I know anything at all outside of my own selves?