Deterministic or probabilistic: U.S. children's beliefs about genetic inheritance

Abstract

Do children think of genetic inheritance as deterministic or probabilistic? In two novel tasks, children viewed the eye colors of animal parents and judged and selected possible phenotypes of offspring. Across three studies (N = 353, 162 girls, 172 boys, 2 non‐binary; 17 did not report gender) with predominantly White U.S. participants collected in 2019–2021, 4‐ to 12‐year‐old children showed a probabilistic understanding of genetic inheritance, and they accepted and expected variability in the genetic inheritance of eye color. Children did not show a mother bias but they did show two novel biases: perceptual similarity and sex‐matching. These results held for unfamiliar animals and several physical traits (e.g., eye color, ear size, and fin type), and persisted after a lesson.

The Role of Visual Representations in Undergraduate Students’ Learning about Genetic Inheritance

“…Further, we found that for both eye color and ear size, undergraduates displayed a sexmatching bias, thinking that offspring are more likely to resemble the parent of the same sex. Both of these biases have also been found in children as young as 4 years of age [22]. These studies provide further evidence that undergraduate students in the United States rely on early-emerging cognitive biases when thinking about genetic inheritance.…”

“…Menendez, Mathiaparanam, et al [21] showed that many undergraduate students believe that animals will resemble the parent of the same sex, even for traits like eye color that are not sex-linked in humans or in any of the animals used in their study. These two misconceptions are evident in children as young as 4 years of age [22]. This suggests that these misconceptions are stable across development and they appear to be resistant to instruction, as college students who have learned about genetics continue to exhibit them.…”