Margorie Ferguson identified four common facial expressions seen on women's magazine covers in 1980: the chocolate box expression with lips together and no smile; the invitational expression with emphasis on the eyes; the romantic/sexual expression with straight faces; and the super-smiler with a big toothy grin. Trevor Millum later categorized five male facial expressions in advertisements: carefree with smiling; practical with concentration; seductive with limited smiling and straight face; comic with exaggerated expressions; and catalogue with a very neutral and straight face. These studies aimed to understand how facial expressions were used to portray particular moods and attract audiences.