Around 60% of differences in GCSE results can be explained by genetic factors, with the same genes responsible for maths, science and the humanities
The study suggests that a weakness in one subject is most likely to be caused by environmental factors, such as teaching, as the genes affecting ability for different subjects are the same.
Results in all subjects, including maths, science, art and humanities, were highly heritable, with genes explaining a bigger proportion of the differences between children (54-65%) than environmental factors, such as school and family combined (14-21%), which were shared by the twins.The article linked below suggests that inheritability of homosexuality is about about 35%; or, in other words, about half the inheritabilty of academic ability (including intelligence, memory, diligence, and curiosity).
I found this article in a post I will not link to. One of the points that the author makes is that "eugenics 2.0" is inevitable. Eugenics 2.0 will target the bearers of specific genes; for example, those involved in violence or low academic ability. While there will be a disparate impact in terms of race and ethnicity, eugenics 2.0 advocates will be able to declare that their motivation will not be racism. Eugenics 1.0, an enterprise of early 20th century Progressives, openly advocated sterilizing of the "unfit" and controlling the population of inferior races. Eugenics 2.0 will not have to and still acheive the same result.
Update: National Security Will Drive Genetically Enhanced Offspring
Eugene Volokh thinks the US will feel pressure to allow offspring IQ boosting or fall behind other nations. It becomes a national security issue if the American population becomes 20 IQ points lower than China, India, and Russia. So expect the national wing of a nation's elites to promote offspring genetic engineering.
In spite of the outliers I expect offspring genetic engineering will lead to brighter, better looking, higher performing, and healthy children and adults. What I'm less sure about is personality traits and moral reasoning circuitry.
Then the rate of human evolution will skyrocket. We live in the final decades of human wild type. Some day wild type humans will be the minority. In some countries that will happen in this century.