When a verb comes after tendency, use the pattern tendency to do something (not ‘tendency of doing something’):
✗ …the tendency of accepting anything written on a piece of paper
✓ …the tendency to accept anything written on a piece of paper
✗ …the tendency of treating the Holocaust as if it had never happened
✓ …the tendency to treat the Holocaust as if it had never happened
When another noun comes after tendency, the usual preposition is towards (not ‘of’):
✗ There is a tendency of isolation in modern society.
✓ There is a tendency towards isolation in modern society.