“…number of friends/family members that smoke) or intrapersonal (e.g. such impulsivity, sensation seeking, rebellion) [17]. One paper [34] only included variables from one domain, while eight papers [33,36,41,44,45,48,49,51] included variables from two domains, and ten papers [31,32,37,38,40,42,43,46,47,50] included variables from all three domains.…”