I would suggest doing the experiment again. Maybe with an odd number of subjects. Either all female or male. Around the same age would probably make a difference. Only if you have time that is. If not I would write both results in the conclusion and state the differences between the subjects and there results. Say how the differences may have changed the results for each subject.
it may sound like im trying to be a know-it-all and trying to sound all professional but im just trying to be helpful.