personality_check_if_chars_have_shared_trait_effect

personality_check_if_chars_have_shared_trait_effect = {
	$CHAR1$ = {
		if = {
			limit = {
				number_of_personality_traits_in_common = {
					target = $CHAR2$
					value >= 1
				}
			}
			if = {
				#If CHAR1 and both have this trait, set the appropriate flag.
				limit = {
					has_trait = $TRAIT1$
					$CHAR2$ = {
						has_trait = $TRAIT1$					}
				}
				save_scope_value_as = {
					name = $FLAG_PREFIX$
					value = flag:$FLAG_POSTFIX$
				}
				save_scope_value_as = {
					name = $FLAG_SUCCESS$
					value = yes
				}
			}
		}
		else = {
			if = {
				#Fallback option if the two characters have no shared traits at all.
				limit = {
					#If we are strictly looking for only shared traits, do not do this step.
					$STRICT$ = no

					#Otherwise, simply find a trait that CHAR1 has which CHAR2 does not have the opposite trait for, then add the appropriate flag to CHAR1.
					has_trait = $TRAIT1$
					$CHAR2$ = {
						NOT = { has_trait = $TRAIT2$ }
					}
				}
				save_scope_value_as = {
					name = $FLAG_PREFIX$
					value = flag:$FLAG_POSTFIX$
				}
				save_scope_value_as = {
					name = $FLAG_SUCCESS$
					value = yes
				}
			}
		}
	}
}

As written in game/common/scripted_effects/00_personality_trait_effects.txt.