Do xenomorphs have a form of self-preservation instinct?

Question

In the movie Aliens there is a scene where an Alien manages to sneak onto a transport carrier, and after the carrier takes off, it kills the crew and also the pilot driving the carrier. After that the carrier naturally crashes, and everything is destroyed, including the alien.

That seems pretty weird. There are two explanations possible:

1. Either the alien is so dumb that it cannot predict the result of its own actions (IQ too low, I guess). But that kind of contradicts everything else in the movie, especially the way the aliens cut off wires before attacking marines.
2. Either an alien does not have a self-preservation instinct and may sacrifice itself in order to achieve a bigger goal (in this case, preventing marines from leaving the planet).

Which variant is more likely to be true?

Answer 1

While John O developed his answer based on your first hypothesis (the alien intelligence) I will develop mine based on the second one (the alien self-preservation instinct).

You said "an alien does not have a self-preservation instinct and may sacrifice itself in order to achieve a bigger goal". Actually, in Alien vs Predator we can see that they indeed may sacrifice themselves in order to achieve a bigger goal when they use their own acid blood to break the chains that hold the alien queen.

Answer 2

In the original movie, Ash speculates that the thing is only as intelligent as a chimpanzee. If he were correct, this would still allow them to be cunning, but unable to predict the consequences.

However, it should be noted that even a primitive (but otherwise intelligent) human would have made the same mistake. If such a human found two others in a metal box sitting on the ground, it would assume that they were inside a metal hut and not a vehicle, and certainly not a vehicle that could fly. So we could be looking at a scenario where the alien is as intelligent as a human being but simply unfamiliar with technology.

A third explanation is also possible. Even if it understood what the dropship was, it may have simply miscalculated. Perhaps it thought it could kill the two pilots before they managed to lift off, but did not expect for the controls to be mashed.

My bet would be on some combination of the latter two explanations above. As for cutting wires, they may have discovered that themselves, in the weeks prior to the arrival of the colonial marines.

Answer 3

In Alien:Resurrection, these creatures broke free from the chamber they were held in after they "agreed" to kill one of themselves. They smashed its skull (or torso - can't remember now) so that its acid blood spilled on the floor and burned a hole there. In that scene, creatures had some kind of "conversation" before doing it. So they are a) smart enough b) value hive or queen more then self (if they have self-awareness at all).