New results are presented on the influence of the structure of surfactant headgroups on the ability of micelles to form shear-induced structures (SIS). Flow birefringence and electric birefringence results are reported on surfactant solutions of alkyldimethylamine oxide (C(14)DMAO) and sodium dodecyl sulfate (SDS) and on solutions in which some of the C(14)DMAO was substituted by C12E6 and the SDS by C12E2.5SO4Na, respectively. In the mixed solutions of C(14)DMAO and SDS, small rodlike micelles are present that show the electric birefringence anomaly. A second process appears in the electric birefringence signal that opposes the first one. The process is observed around the overlap concentration of the rodlike micelles. Under shear, solutions that give rise to the electric birefringence anomaly show anomalous flow behavior. For shear rates (gamma)over dot above a critical shear rate (gamma)over dot (c), the solutions show the phenomenon of shear-induced structure formation. The solutions are shear-thickening for (gamma)over dot > (gamma)over dot (c). The flow birefringence results show that for (gamma)over dot > (gamma)over dot (c) a fraction of the micelles is completely aligned in the direction of flow. The SIS disappears with increased substitution of C(14)DMAO by C12E6 and of SDS by C12E2.5SO4Na, while the electric birefringence anomaly does not disappear. It is therefore concluded that the SIS formation is related to adhesive contacts between micelles.