Sassafras Arching Trunks

Trees such as sourwood, black gum, and river birch often having a pronounced bend to their trunks. I've always assumed that it is a phototrophic response whereby the stems are simply growing towards the area where light is most readily available. But in the Sassafras trees growing in our home landscape (Clemson) something else seems to be going on. In the last 5 years or so there have been two years in which the female trees have had a super abundant fruit crop and the weight of all those developing fruits caused the stems to bend downward during the several weeks that the fruits matured. These periodic heavy fruit loads, I believe, contribute to the permanent bend often seen in Sassafras trunks. Additional support for this hypothesis is that male trees, which lack the burden of producing weighty fruits, generally have much straighter trunks than do the females, at least in our landscape. It would be interesting to see if this pattern holds true for Sassafras "in the wild".