In a study conducted in 2012, researchers investigated how having positive words presented at the top of a screen and negative words presented at the bottom can change the way our brains work to understand things. In the primary task, 68 participants had to categorize words as positive or negative, as quickly as possible, when words would appear at the top or the bottom of a screen. The analytical approach involved comparing categorization times in regards of word positions (authors refer to a “General Linear Model”). Confounders like word length, or number of syllables were controled. Among other hypothesis, the primary hypothesis which posited that the speed of categorization of words would depend of their position on the screen (experiment 1), was supported by the results with a large (p. 18) effect size. This overview provides a concise synthesis of the most relevant results. For more details, please refer to the article page.
Users might process information faster if positive words are placed higher on the screen and negative words lower. Keep in mind that negative words may be harder to process for end users.
Lakens, D. (2012). Polarity correspondence in metaphor congruency effects: Structural overlap predicts categorization times for bipolar concepts presented in vertical space. Journal of Experimental Psychology: Learning, Memory, and Cognition, 38(3), 726–736. https://doi.org/10.1037/a0024955