While it is true the major mode of action of the medicines we call the SSRI's is at a subtype of the serotonin auto-recptor, it is not correct to generalize that any behavior changed by an SSRI must be under the control of serotonin.
Serotonin is a wide ranging neurotransmitter, and appears to have an effect on each of the myriad of other known neurotransmitters. It may be closer to what we think of as a neuromodulator than a specific transmitter for many systems. We do know that if functions as a strict neurotransmitter in some actions in the gut and the temperature regulation system, but it appears to have more general actions as well, especially when it is effected by exogenous medications.
When we consider the time delay between when the medicines start to change serotonin levels in the synapses and when the clinical responses are observed, it becomes quite likely that many of the effects of an SSRI are actually the results of changes in other transmitter systems that are "downstream" from serotonin, such as dopamine.
Thus, though we know that SSRI's have effects on bonding, shame, rejection sensitivity, dominance, etc., it does not mean that all of these are regulated by serotonin. For instance, dominance might be more under the control of say dopamine, and the changes seen by to produced by the SSRI's are due to effects that changes in serotonin have on the dopamine system in various tracts.
Also remember, it is unlikely anything as complex as a behavior or trait is under the control of a single neurotransmitter. It's just that if a single transmitter is changed significantly, changes are produced in all the other systems as well.