Adapting Food Preferences: The Social, Emotional, And Genetic Roots Of Preferences For Meats versus Plants
Authors:   , Çınar Çağla 
Published: February 2024

We vary in what we choose to eat and what we choose not to eat. The current dissertation sheds light on the psychological factors that underlie food learning and discusses the social, emotional, and genetic foundations of food preferences. In four empirical chapters, I apply concepts and methods from the literature on (specialized) learning and learning strategies (e.g., social information, previous food experiences, associative learning) on meat and plant preferences. Our empirical research illustrates the relevance of disease avoidance systems to food selection as well as new insights into the ways the unfamiliarity of food interacts with decision-making or learning processes. Chapter 2 gives a fresh perspective by differentiating food neophobia (wariness towards unfamiliar foods) toward various meats and plants. In four studies (N’s = 210, 306, 160, and 161), I demonstrate that both sexes have comparable levels of food neophobia toward plants, but women compared to men have higher levels of food neophobia against meats. Our study is the first to reveal how individual difference characteristics interact similarly or differently toward meat and plant neophobia. Chapter 3, which examines the genetic and environmental foundations of meat and plant preferences, demonstrates that within-population preferences for meats and plants are heritable, but only somewhat result from common environmental factors. Data from 9319 Finnish twins and siblings of twins resulted in heritability factors for childhood meat consumption (h2men= .31, h2women= .11), current meat preferences (h2 men = .26, h2women = .51), childhood plant consumption (h2men= .41, h2women =.17), current plant preferences (h2men = .45, h2women = .53), meat neophobia (h2men = .48, h2women = .55) and plant neophobia (h2men = .56, h2women = .54). Genes underpinning childhood meat consumption and current meat preferences (but not childhood plant consumption and current plant preferences) vary between the sexes. Results indicate no sex-specific differences in the heritability of meat neophobia (or plant neophobia). In four studies (N’s = 515, 495, 164, 175), Chapter 4, examines specialized learning, and tests if there is a specialized mechanism that enhances learning foods with pathogen-specific images as compared to other negative images. Focusing both on explicit attitudes and implicit attitudes towards food and non-food items, this chapter shows a pattern consistent with evaluative conditioning effects, such that negative images result in less liking to the images they are shown with. While the individual results from the studies do not support a fully specialized mechanism that affects attitudes towards foods (and especially meats) more strongly, a mega-analysis indicated a specialized learning mechanism for meats. Chapter 5 manipulates food experiences from social counterparts in two studies (N’s = 215, 212), and tests if positive and negative consequences are recalled differently for meats and plants as well as for familiar and unfamiliar foods. Using signal detection theory, I also examine potential biases in linking negative consequences to unfamiliar as opposed to familiar foods, and to meats as opposed to plants. Contrary to expectations, participants demonstrate better accuracy in remembering positive outcomes compared to negative ones. Moreover, familiar foods are recalled better than unfamiliar ones. Signal detection analyses point to a tendency to associate unfamiliar foods with negative consequences. Furthermore, participants anticipate enjoying foods linked to negative outcomes less than those connected to positive outcomes. Chapter 6 discusses these findings concerning their theoretical implications in disgust and food research, as well as their practical implications in introducing meat alternatives for a sustainable future, and suggests clinical strategies informed by our research, emphasizing their potential in addressing eating disorders, with a specific focus on Avoidant/Restrictive Food Intake Disorder (ARFID).