Complex sentence: In the mid- 20th century psychologists such as Hans Eysenck developed a personality profile for the typical smoker of that period; extraversion was associated with smoking, and smokers tended to be sociable, impulsive, risk taking, and excitement-seeking individuals.
Split into simpler sentences: In the mid- 20th century psychologists such as Hans Eysenck developed a personality profile for the typical smoker of that period. Extraversion was associated with smoking, and smokers tended to be sociable, impulsive, risk taking, and excitement-seeking individuals.