The phrase "was predisposed" can be replaced with a number of synonyms that convey a similar meaning. Some alternatives include "inclined", "prone", "disposed", "susceptible", "apt", and "likely". Each of these synonyms implies a preexisting tendency or susceptibility towards a particular behavior or situation. Additionally, one might use more informal language, such as "was geared towards", "had a natural affinity for", or "was wired to". Using synonyms for "was predisposed" adds variety to one's writing and may help to convey a more nuanced understanding of human behavior and motivation.