Overall was born in Te Kūiti in 1974 and completed a PhD titled Why do people try to change their intimate relationships?
: the regulation function of ideal standards at the University of Canterbury, supervised by Garth Fletcher.
[1][2] After completing her doctorate, Overall joined the faculty of the University of Auckland, rising to full professor.
[8] Overall is especially interested in communication strategies used by couples in relationships to overcome conflict.
[4] Overall has served on the editorial boards of a number of journals, including the Journal of Personality and Social Psychology and Personality and Social Psychology Bulletin.