It is estimated that genetics account for about percent of the inclination to begin smoking, and for about percent of the ability to quit.

"It is estimated that genetics account for about 75 percent of the inclination to begin smoking, and for about 54 percent of the ability to quit."

According to Caryn Lerman, a professor of psychiatry that has done much research in neuroscience, pharmacology, genetics, and behavioural science with the objective to better the treatment for tobacco dependence, 75% of the inclination to begin smoking is from genetic base, and 54% of the ability to quit is also from genetic base.