While watching his older sister dive into a swimming pool, jackson saw her slip on the end of the diving board, crack her head on the end of the board, and end up bleeding in the pool and crying hysterically. she required 12 stitches to close the cut on the back of her head. as a result, jackson was highly afraid of both diving boards and the deep end of swimming pools. he did not overcome these fears until he was well into his early adult years. jackson acquired his phobia as a result of conditioning?