Frizz and static electricity of hair are the two ends in the "spectrum" of moisture. With excess moisture hair frizz, and when insufficient, presents the phenomenon of static electricity. The hydrated hair have the ability to dissipate electrical charge, so under high humidity conditions the hair frizz, but does not accumulate electric charge. Because too dry hair does not have enough water to release the accumulated electric charge, the hair repel each other, causing static electricity - each hair has accumulated a large amount of negative charge and is removed from the other. You may notice that the days that your hair have static electricity, you may experience minor electric shocks every time you touch metal objects. This is the way your body releases the accumulated electric charge.
It is very interesting that the products against frizz and products against static electricity are sufficiently similar in their composition. In both cases, a kind of barrier to better control the movement of moisture and retaining it in the areas where they need - either externally (products against frizz), or internally (moisturizing products against static electricity).