One dimensional quantum mechanical systems known as spin chains provide the connecting link between gauge theories and string theories. More precisely, the common spectral problem of the gauge and string theory entering the AdS/CFT correspondence appears to be described by an integrable spin chain. The prevailing oppinion is that integrability has to break down when one takes into account non-planar corrections in the gauge theory and correspondingly string interactions in the string theory. We will try to quantify this statement.