Malenfant does have a point, though. In many human cultures, humans have rights from the time they are born. Rights reflect cultural attitudes, and many of the cultures that we are familiar with grant certain rights to infants because it is important to the culture to do so.
There are also cultures historically that did not grant rights to humans below the age of eight, or even certain races of humanity because of their origin or appearance, and that's just here on this planet. (Slavery as practiced by the western world in the 1600's through 1800's springs to mind far too easily.)
Sentience in not automatically related to whether or not an entity has rights, though more empathic creatures will tend to feel an obligation to bestow rights on other sentience.
I've always had the opinion that the Third Imperium holds androids as second-class citizens at best, despite the fact that Traveller defines them as created biological lifeforms. I imagine it all depends on whose on the Iridium Throne at the time, really...
"Soapbox" issues like this, unresolved in the OTU, give us fodder for adventure opportunities and campaign scenarios. I like it unresolved, because it creates conflict, and conflict generates action, and action makes the campaign go 'round.
More later,
Flynn
