Because notions of equality can change over time, it cannot be ruled out that the vision of a two-tier society of enhanced individuals on the one hand and unenhanced individuals on the other might one day lose its shock value. Should the view eventually prevail that the benefits of certain neuroenhancement drugs far outweigh the potential harm, those who do not want to use them might be socially marginalized in a similar (or even more dramatic) fashion as people who refuse to use mobile phones today. Their fears of unknown side effects of neuroenhancement drugs would be considered as irrational as the fear that mobile phone radiation may cause brain tumors today. A liberal society would, of course, not force anyone to take neuroenhancement drugs against their will; but it might consider it a self-inflicted and therefore not unjust disadvantage if the minority of enhancement opponents no longer had access to certain social positions.

While in the case of pharmaceutical neuroenhancement, individuals can at least compensate for their competitive disadvantages compared to enhanced competitors by more or less voluntarily resorting to neuroenhancement drugs themselves, this possibility would not apply in the case of genetic enhancements. If traits were optimized by intervention in the germline, influential positions might only be open to people whose parents have made them genetically fit for this purpose. Because the enhanced individuals would pass on their advantages to their descendants in the sense of a hereditary privilege, an extremely impermeable two-tier society could be created.