Geraniums have been popular garden perennials for a long time, and have lots of devotees. Consequently, there are lots of good sources of information on the internet. A good start is provided by the Open Directory Project's geranium category. For a primer on erodiums, this page from the UK gives a good overview.
Stimulus control is the phenomenon of a stimulus increasing the probability of a behavior (operant response) because of a history of that behavior being differentially reinforced in the presence of the stimulus.
Behavioral regulation scales. 1  Inhibit: Ability to control impulses (inhibitory control) and to stop engaging in a behavior. 2  Shift: Ability to move freely from one activity or situation to another; to tolerate change; to switch or alternate attention. 3  Emotional Control: Ability to regulate emotional responses appropriately.