This article deals with the prospect of genetically enhancing intelligence. We identify and contrast social attitudes (disapproval) to the use of future genetic technology with social attitudes (approval) for environmental methods of enhancing intelligence. Using various forms of the argument that the means by which enhancement is achieved has moral significance, we look for differences that could justify the different attitudes. We find that the different attitudes cannot be ethically justified. We predict that the lack of ethical justification for distinguishing between means of enhancement is likely to result in the eventual acceptance of genetic enhancement of intelligence.