The main research objective of this work is to identify possible channels through which socioeconomic status proxied by education influences the risky health behaviours: smoking tobacco, alcohol abuse and consumption and overeating. Econometric estimations on each of these bad habits shows that measures of cognitive ability, attitude towards life, social integration, description of the main job and the monthly household income together explain over 67% of the negative smoking gradient by education, 77.5% of the differences in at least occasional alcohol consumption but only around 6% of the negative gradient on being obese. The relationship between heavy alcohol abuse and education is against all expectations a positive one and only some measures of attitude towards life and social integration reduce the probability of alcohol abuse. Furthermore, the newly introduced additive theory which states that an individual accumulates risky health behaviours reflecting, and hence explained by, personal characteristics is tested. The results of the econometric analysis confirm that schooling has a negative effect on cumulating bad habits. It is shown that the level of education has little impact on picking up one unhealthy habit, whereas the chance of adding another one or two to this vice on average increases by about 8% with each level of education.