Valence conveyed in simple geometric shapes I've seen neuroscience and facial recognition studies that give evidence for this idea of simple geometric shapes causing emotional responses or quicker recognition of negative affect.  

Are there studies exploring the other end? (i.e. positive valence of simple geometric shapes)


Larson, C. L., Aronoff, J., Sarinopoulos, I. C., &amp; Zhu, D. C. (2009). Recognizing threat: A simple geometric shape activates neural circuitry for threat detection. Journal of cognitive neuroscience, 21(8), 1523-1535.
Watson, D. G., Blagrove, E., Evans, C., &amp; Moore, L. (2012). Negative triangles: Simple geometric shapes convey emotional valence. Emotion, 12(1), 18-22. doi:10.1037/a0024495
I love this kind of research because it shows how there's an affective undercurrent to essentially every part of our lives.  This is formalized in microvalence theory (Lebrecht et al., 2012), which posits that all objects, even ordinary ones, are imbued with valence (e.g., explaining why you prefer one chair over another).  

As far as positive geometric shapes, there is evidence for consistent positive reactions to circular and curvilinear shapes (e.g., Bar &amp; Neta, 2006; see also Larson, Aronoff, &amp; Steuer, 2011).  There may be some obvious top-down mechanisms mediating this effect, such as positive associations with a smile (vs. a frown; Salgado-Montejo, 2015).