I dunno, I think your definition is as good as any.
Ultimately, there is no objective definition, even to NTs. Ask ten people what love is, and you'll get 10 different answers. If NTs can't even agree on the definition, then asking the question whether non-NTs can or can't feel it is rather academic, since there is no agreed upon standard by which to compare. Moreover, if there is a capability, it is quite possible that the lack of this capability is not a defining characteristic of all aspies, and it is also possible the relation is due to some other complicating factor such as depression or anxiety that are common co-morbid conditions, or there is no relation between the two at all.
It seems to me that this question is rooted in the gap between the internal world and the external world which plays such an important role for us on the spectrum. I think we can feel anything an NT can feel, but since the dividing line between our inner and outer realities is so much more stark than NTs, it's often more difficult to translate what we're feeling internally into some outward expression, and it's also more difficult to interpret and reciprocate feelings of love and attraction directed toward us because we are more apt to misinterpret the information, and take longer to process it. The process of love is thus slower, more drawn out, and more fraught with potential confusion and conflict.
Much of psychology still functions by establishing a norm for behavior based on the majority and defining all deviations sufficiently far from this norm as some level of dysfunction. It is easy to conclude that love does not exist for the aspie when it is defined by observations taken mainly from NTs. It is easy to overlook the fact that a process involving one person with a vastly different psychology will probably look so different from the norm, it may not even be understood as what it is. Imagine if aliens crashed on earth about 500 years ago before biology was well understood. Further, imagine that their blood was green rather than red. Scientists would no doubt disagree on the nature of this green substance. Some would say that it must be that they had no blood, since we have not observed blood in any animal to be of any color other than red, while others would maintain that the green substance was blood, and that our definition of "blood" must be changed to fit this new situation. I think perhaps that aspie love is sufficiently different than NT love, it may not be readily recognized as such.
Furthermore, consistent failures in this and other social arenas from an early age lead to anxiety and fear related to these issues. We get a lot of advice from people who mean well but who are basing their advice on NT assumptions which are not valid. We doubt ourselves because we see how different we are, and it is quite natural and logical for one to conclude that the deficiency is likelier to be in the minority than the majority. Our natural process thus gets further corrupted when we attempt to be more "normal", and we can easily conclude that we are incapable and simply give up or decide the reward isn't worth the effort. The many aspies that do this lend further credence to the idea that we are incapable of love, and the vicious circle repeats.
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Self-Diagnosed Dec. 2010
135 Aspie, 65 NT--Aspie Quiz
AQ 40
BAPD--124 aloof, 88 rigid, 83 pragmatic
EQ/SQ--21/78--Extreme systematizing