Yes, language and religion are heritable. Environmental biases can have an effect. No kidding, Sherlock. The researchers are aware of this that's why they look

Yes, language and religion are heritable. Environmental biases can have an effect. No kidding, Sherlock. The researchers are aware of this that's why they look for correlations across different environments. To use your example, if a gene still has the same correlation even among non-brown eyed people or the same correlation appears even in societies that don't discriminate against people with brown eyes that's a different story. Thats what these researchers are doing. These observations aren't made in one environment. They happen across different cultures, different classes, different societies, etc. Factors like parental educational attainment can be adjusted for.