The bond thermal expansion is in principle different from the lattice expansion and can be measured by correlation sensitive probes such as extended x-ray absorption fine structure (EXAFS) and diffuse scattering. The temperature dependence of the coefficient αbond(T) of bond thermal expansion has been obtained from EXAFS for CdTe and for Cu. A coefficient αtens(T) of negative expansion due to tension effects has been calculated from the comparison of bond and lattice expansions. Negative lattice expansion is present in temperature intervals where αbond prevails over αtens; this real-space approach is complementary but not equivalent to the Grüneisen theory. The relevance of taking into account the asymmetry of the nearest-neighbours distribution of distances in order to get reliable bond expansion values and the physical meaning of the third cumulant are thoroughly discussed.