Aggressive is related to War. Aggression is part of War. Aggression is related to Psychology. 
Farm is related to Side. Side is related to Nature. Nature is related to Environment. 
Aggressive <--RelatedTo--> War <--PartOf-- Aggression <--RelatedTo--> Psychology 
Farm <--RelatedTo--> Side <--RelatedTo--> Nature <--RelatedTo--> Environment 