Why is polarity a key connection between the structure of a molecule and its properties?

The intermolecular force of the molecule is determined by the polarity of the molecule and hence the physical properties of a molecule are affected. As polar molecules would have stronger intermolecular forces than non-polar molecules, they have higher boiling points, freezing points and surface tension. Further, a polar molecule would retain an assymmetrical structure while non-polar molecules will be symmetrical. Hence polarity determines structure of molecules and its properties.