Several studies with Spontaneously Hypertensive Rats (SHR) implicate reinforcement and extinction deficits as their main differences from other lineages. In this paper, data of six experiments were revised to address these main deficits. On experiment 1, SHR were compared to Wistar rats in a multiple FI-Ext schedule of reinforcement, results failed to replicate differences between lineages. This result could be related to inadequate behavior of control group, as well as absence of a feedback light that is commonly used. To investigate these two hypotheses, two experiments investigated both the feedback light (FBL)condition and the control group used. These experiments didn’t show an FBL effect, but replicated differences among lineages (SHR, Wistar and Wistar Kyoto). An interesting finding is that SHR received more reinforcers than other strains, on FI component. Two other experiments investigated conditioned reinforcement on SHR and controls but didn’t indicate a conditioned reinforcement (CR) deficit or a sensory reinforcement hypersensitivity, as is usually suggested by the literature. Experiment 4 raises the hypothesis of a deficit on the extinction of CR. Experiment 6 revealed consistent differences on extinction of a food-maintained response. Together, experiments point to a major deficit on extinction, but does not support alterations on reinforcement processes.