What would happen if scientists used different physical characteristics

Besides their functions, one helps the development of sexual characters and the maduration of gametes, and the other is used during stressful situations to promote self-preservation, stress hormones act quicker than sex hormones. Also, all sex hormones are steroid hormones (meaning they are composed of a 4-carbon-cycles core), while stress hormones have only one steroid hormone, the others being catecholamines (a mono amine with an aromatic cycle). Some stress hormones are also used as neurotransmitters on the body.

Sex hormones: testosterone, estriol, progesterone
Stress hormones: adrenaline, noradrenaline, cortisol