Since times immemorial, humans have separated themselves into two herds, the strong and the weak. And trust me when I say this, there is no gray zone when it comes to strength and weakness. It's either white or black, always has been, always will ever be.
In ancient societies, brute strength reigned supreme. The bigger, the stronger, and the meaner were revered as chieftains and champions from even before the Neolithic era all the way across the early bronze ages. They formed the upper warrior castes of primitive societies and controlled those who were weak, pushing the service roles on them.
Society evolved, however, and strength took many different forms such as wealth, magic, or faith. Those who had strength still trampled over those who lacked it but even with how far strength evolved, the primitive forms of strength were nothing to scoff at.