Untrained women tend to have around 25 percent body fat, while untrained men tend to have around 15 percent body fat. Body fat is spread throughout the body, which means that on average, women have more fat on their thighs than men. This makes their thighs literally softer because their body fat gives women less muscle definition than most men have.
Masculine and feminine thighs are also different because of the male capacity to develop greater muscle mass. Men put on more muscle than women do. So, if a man and a woman have similar body fat, the man will still have larger thighs with clearer muscle definition because he is able to put on more muscle than his female counterpart. Even if the definition is the same due to the same amount of body fat, the man will still have physically larger thighs.
Women deposit more fat around their thighs and buttocks than men do; women's bodies store fat in the thighs as a reserve for the energy needed for lactation. This means women have more fat in their thighs than men and therefore have bigger thighs in proportion to their body size.
Shape and Pelvis
Men and women have different pelvis shapes. The pelvis, the bone that connects the upper body to the lower body, gives men and women their distinctive hip shape. In general, women tend to have wider hips due to a more circular pelvis. Wider hips mean a different thigh shape, as thighs are directly connected to hips. So, size, shape, fat and muscle aside, feminine thighs tend to have a different, more rounded shape than masculine thighs because of the outward flare of the hip bones.