Sharp-cornered objects caused much greater amygdala activation than rounded objects. A well-studied region in the temporal lobe of the brain, the amygdala’s primary function is to process stimuli that induce fear, anxiety, and aggressiveness and to deal with the resulting emotional reactions. In other words, angular shapes tend to trigger fear and therefore aversion and dislike. Moreover, the authors of the study noted that “the degree of amygdala activation was proportional to the degree of angularity or sharpness of the object presented, and inversely related to object preference”.

Lima, M. (2017)

A sharp angle is associated with ‘shocking’ or ‘exciting’, because of the acute change in the direction of the movement. However, a rounded corner is seen more as ‘relaxed’ (Kreitler and Kreitler, 1972).

The size of an angle can be determined by measuring the angle that two lines make with each other. This angle can be expressed in both degrees and radiants. The larger the angle, the more blunt it is. And conversely, the smaller the angle between two lines, the sharper.

The emotional effect of sharp corners differs according to the application. When it comes to utensils, sharp corners can be perceived as dangerous, they can puncture or cut.

Blunt/sharp is classified as a HEIGHT dimension parameter because a shape with blunt lines comes often with a thick shape, while sharpness appears most of the time in a thin shape. Compare the thick/thin parameter.

(Inez Michiels, DSD, 2021)