In this episode, Jess and Sara finally (Finally!) tackle the basic premise of behavior genetics. We talk about what kinds of research questions you can ask with genetically sensitive designs, describe what heritability is and what it’s not, and discuss just how it’s possible that scientists can use data from twin pairs to understand how much of the variance in some skill or behavior is due to genes and how much is attributable to the environment. A lot of that estimate depends on just how much genes and environments vary within a twin pair and between twin pairs (see what we did there?). In this episode we talked about: Sara’s paper with the figures that Jess describes: https://www.nature.com/articles/s41539-020-00079-z/figures/3 Here’s a cool introductory paper written for Frontiers for young minds that covers much of this introductory content: https://kids.frontiersin.org/articles/10.3389/frym.2019.00059 Connect with the podcast on twitter @within_between, or email us letters about developmental science at [email protected]. More episodes and podcast information at WithinandBetweenPod.com. Follow Dr. Hart on twitter @Saraannhart Follow Dr. Logan on twitter @Jarlogan. Our theme music was composed by Jason Flowers. Our logo was created by Nathan Archer. Recorded November 28, 2021.