Answer: Tammy's father is an exceptional gymnast. When Tammy was just a toddler, her father believed that Tammy already showed great promise as a gymnast. Tammy's father probably believes that athletic ability is mostly determined by GENETIC FACTORS.
Explanation: Most traits are produced by genetic factors. There are some produced by environmental factors while others are produced by combination of genetic and environmental factors.
Genetic factors are those factors that can be passed from parents to offsprings. For Tammy's father to have believed that Tammy would be a great gymnast when he was still a toddler and has not passed through any form of gymnastics training, he must have thought that Tammy has inherited gymnastic ability from him.