Seventeen-year-old Gina typically makes good decisions and stays out of trouble. Her parents were surprised one night to discover that Gina had snuck out of the house, knowing that if she were caught she would be grounded and would lose her driving privileges and the use of her cell phone. When questioned about her decision to sneak out, Gina told her parents that her best friend was having a hard time. Gina told her parents that she "had to" go talk to her friend at 3:00 A. M. and that nothing else mattered. Gina seemed to have made her decision to sneak out based on thinking.

Paula maintained her normal weight during her freshman year in college. during her sophomore year, she moved into an apartment with two friends who are overweight. the three regularly enjoy high-calorie meals together, and paula has gained more than twenty pounds. she wants to lose weight, but it seems as if, whenever she plans to prepare a healthful, low-calorie meal, her roommates come home with a box of pizza or take-out burgers and fries. what type of influence are her friends having on her behavior? social undermining moral support emotional encouragement informal persuasion social undermining