In most cases jealousy is taken up as a norm or character in someone. Selfish on the other hand might mean something different but all have something in common of which deals with self interest .
Therefore the seventh sense is just but jealousy and selfishness all together. In three out of five people, they in habit both either jealousy and selfish. In most cases it may not be evidently expressed but in some instance and cases it may be triggered.
Jealousy /selfishness as a sense may not involve anybody organ but it may be expressed either physically, mentally and word of speech. It is a sense associated with feelings of which occur in every human, as we all tend to variety in terms of feelings on a day to day basis.
So what more about the 7th sense,it may not be scientifically proven but in the near future i may put it in petition with better findings.