Environmental factors that influence smoking habits of monozygotic and dizygotic twins

Abstract

Smoking habits are influenced by environmental (family, friends) and psychologic factors. To investigate environmental factors which influence the smoking habits of monozygotic and dizygotic twins. 45 monozygotic and 23 dizygotic twin pairs (age 35±16 years) completed a questionnaire. Maternal non-smoking decreases the risk of smoking of the twin children by 53%, while this effect accounts for 49% by the father. Dizygotic twins are more influenced by parents (70%) than monozygotics (31-36%). If the twin or non-twin sibling does not smoke, the risk that the twin individual starts smoking, is decreased by 86% both in monozygotic and dizygotic twins. If an individual smoking is present in the fraternity and he or she does not attempt to quit, the risk of smoking increases 8.3-fold. The role of fraternity is more important in males and youth. The parents' and the siblings' exemplary behaviour helps to avoid smoking initiation of young twins.