WHY ELCTRON FLOW IN DIPOLE TOWARDS POSITIVE CHARGE ?PLEASE EXPLAIN BRIEF...

BOTH ARE just convention , possitive and negative are simply lebel of two diffrent kind of charge without any deeper significance attached to them , since , we arbitarily assigned it , we have given all out direction like field, potential , etc from +ve to -ve , if we simply interchange these lebels then our physics will not going to change . 
actually there is no perticular way , but still u can understand by the following logic .
while fiunding the direction of torque right hand screw rule is used in the cross product obviously , it has been assumed that to satisfy that rule , we have to Assume direction of dipole moment from negatve to posstive , 
HOPE IT CLEARS YOUR DOUBT ..