Lisping and other such speech impediments may have to do with deficiencies in the endocrine system and hormonal imbalance, which may in turn be tied to unfavorable environmental factors that stunt normal development, such as pasteurized and chemically processed dairy products and meat (or non-meat, like "pink slime").
If you add to the above psychological developmental factors such as broken homes, a defective, negligent, abusive or absent father (which is the model a boy has for his masculine identity on the natural level), the noxious influence of mass media that is at once hyper-sɛҳuąƖ and gynocentric (creating a problematic bifurcation of personality wherein a young man becomes engrossed in impurity as a way to assert a false masculinity, which ironically makes him all the more vulnerable to being dehumanized and emasculated by hyper-feminizing and infantilizing trends that have infiltrated "pop-culture"), &c.: then you get a a glimpse of the core problem that is subverting the very foundations of civilization.