Minecraft wiki entry for Panda, associated text: Each panda has two hidden values called "genes" or "alleles", similar to biology. There is the main gene and a hidden gene. Normal, aggressive, lazy, worried, and playful personalities are dominant traits, and weak and brown personalities are recessive traits. A dominant trait always has priority over a recessive trait. If both the main and hidden genes are dominant, the main gene has priority and presents itself as the panda's personality. Being recessive, weak and brown personalities occur if both the main and hidden genes of a panda are recessive genes. However, if the main gene is recessive and the hidden gene is not the same gene, then a normal personality results. To get a brown or weak panda, both the main and hidden genes must be both brown or weak.