Genetics and biology are additional factors that influence academic performance. One child may have an identical upbringing to another child, but faces the challenges of a learning disability such as attention-deficit/hyperactivity disorder, ADHD, or dyslexia. A child's gender may make them more likely to achieve in math and science (boys) or language skills (girls) (Siegler et al., 2014). Gender plays a role in how environmental influences affect children. Boys are more likely to be negatively affected by low-income status than girls in their studies (Siegler et al., 2014). They are also more likely to get higher test scores when their parents have a higher education. A recent study has shown that genetic factors do not influence the academic success of boys more than of girls. This is likely due to efforts to equalize education for both genders (Orstavik, Czajkowski, Røysamb, Knudsen, Tambs, & Reichborn-Kjennerud, 2014). A study from Taiwan concluded that birth order and gender are greater factors of success in families with parents with higher education levels (Cheng, Wang, Sung, Wang, Su & Li 2012). This supports the theory that these parents may have more resources and time with firstborns and possibly higher expectations