Professor Brad Bushman wrote an article for Science Trends about the “weapons effect” – the idea that seeing weapons can prime aggressive thoughts. Bushman’s article was based off his 2018 meta-analysis of findings from weapons effect studies from 1967 to 2017.  According to Bushman, the presence of weapons increases aggressive thoughts, hostile appraisals and aggression, which suggests a cognitive route from weapons to aggression, according to the General Aggression Model.