synergise_friendship_interaction_bonus_individual_effect

synergise_friendship_interaction_bonus_individual_effect = {
	$SENIOR_CHARACTER$ = {
		# Diplomacy education.
		if = {
			limit = { has_trait = education_diplomacy }
			add_character_modifier = fp2_single_synergy_diplomacy_modifier
			$JUNIOR_CHARACTER$ = { add_character_modifier = fp2_single_synergy_diplomacy_modifier }
		}
		# Martial education.
		if = {
			limit = { has_trait = education_martial }
			add_character_modifier = fp2_single_synergy_martial_modifier
			$JUNIOR_CHARACTER$ = { add_character_modifier = fp2_single_synergy_martial_modifier }
		}
		# Stewardship education.
		if = {
			limit = { has_trait = education_stewardship }
			add_character_modifier = fp2_single_synergy_stewardship_modifier
			$JUNIOR_CHARACTER$ = { add_character_modifier = fp2_single_synergy_stewardship_modifier }
		}
		# Intrigue education.
		if = {
			limit = { has_trait = education_intrigue }
			add_character_modifier = fp2_single_synergy_intrigue_modifier
			$JUNIOR_CHARACTER$ = { add_character_modifier = fp2_single_synergy_intrigue_modifier }
		}
		# Learning education.
		if = {
			limit = { has_trait = education_learning }
			add_character_modifier = fp2_single_synergy_learning_modifier
			$JUNIOR_CHARACTER$ = { add_character_modifier = fp2_single_synergy_learning_modifier }
		}
	}
}

As written in game/common/scripted_effects/03_dlc_fp2_scripted_effects.txt.