Why Being Luke’s Father Mattered

How evolutionary psychology helps us better understand Star Wars.

Posted Sep 08, 2015

Spoiler alert: Darth Vader is Luke’s dad!

If you’re like me, then finding this information out on the big screen (perhaps when you were a kid) was one of your greatest cinematic moments. Wow! Big news.

With the coming of the new "Star Wars" trilogy, I got thinking about "Star Wars." And, being me, I got thinking about how evolutionary psychology helps us better understand the "Star Wars" saga.

Return of the Jedi (and a Lesson on Kin-Based Altruism)

I think it wasn't until I was like 40 when I realized that the term “Jedi” in the title of Episode VI (Return of the Jedi) referred to Anakin Skywalker/Darth Vader. It’s actually a crucial point of the whole saga. When Anakin was young, he had some good in him, but then he did the old “go to the dark side” thing, as we all know. So Darth Vader essentially was a fallen Jedi knight.

At the end of Return of the Jedi, Vader is losing his energy, engaged in a crazy battle with Luke (his biological son) and the film's epitome of evil, Emperor Palpatine (Darth Sidious). Sidious is about to kill Luke Skywalker.

And then it happens. With his very last bit of energy — and some help from the force — Vader uses some supernatural zapping power to end Sidious once and for all. He kills his master but spares the life of his son.

When Push Comes to Shove, Family Ties Matter

In classic research on the effects of kin-relatedness on altruism, scholars such as Hamilton (1964) argued that organisms have evolved to help genetically related kin – due to their shared genes. In other words, if you are my son, and I help you, then I am helping unique replicas of my genes that exist in your body. In research on kin-selected altruism in humans, Burnstein, Crandall, and Kitayama (1994) found that emergency situations tend to exacerbate the tendency to help kin. That is, when push comes to shove, our proclivity to help kin over non-kin is bolstered. Like all organisms, we have evolved to facilitate the reproductive success of genes that reside within us.

This all can clearly explain Vader’s decision regarding how to use his last bit of energy. Sure, Luke was kind of a wimpy kid and Vader never had much to do with him anyway, but all that aside, blood is thicker than water. Further, think about the situation. Vader had a choice to either save his own son or to save the Dark Sith. Talk about push coming to shove! It makes good sense that kin-based altruistic processes would kick into gear right about then, right? And I’m going to guess that the upcoming films (including "Episode VII: The Force Awakens") may have some genetic descendants of Anakin Skywalker running around — as evidence of the adaptive nature of kin-based altruism.

Evolutionary Psychology Opens Our Eyes

A great thing about the field of evolutionary psychology is that it provides a unique yet powerful way to understand what it means to be human (see my brief textbook, Evolutionary Psychology 101.) As a dyed-in-the-wool evolutionary psychologist, I can’t help it — I see this stuff everywhere! And it helps me to see things through an evolutionary lens. Why is “the Jedi" in “Return of the Jedi” Anakin Skywalker? And what exactly defined the parameters of his return? 

From an evolutionary perspective, it becomes clear. The second that Darth Vader decided to spare his son and take down the Sith, he stepped back from the Dark Side and, in that one altruistic act, he went from Darth Vader back to Jedi Knight Anakin Skywalker (although he still looked pretty nasty under that helmet!) And the evolutionary perspective helps us understand why.

"The Force Awakens" is out December 18.


Burnstein, E., Crandall, & Kitayama (1994). Some Neo-Darwinian Decision Rules for Altruism Weighing Cues for Inclusive Fitness as a Function of the Biological Importance of the Decision. Journal of Personality and Social Psychology, 67/5, 733-789.

The Force Awakens (2015). Directed by J. J. Abrams.

Geher, G. (2014). Evolutionary Psychology 101. New York: Springer.

Hamilton W.D. (July 1964). The genetical evolution of social behaviour. I. J. Theor. Biol. 7 (1): 1–16.

*** Special thanks to my kids, Andrew and Megan, along with their Cousin/Pal Enso, for getting me into Star Wars again. And special thanks to my star alum, Kimberly, who opened my eyes to the art of using evolutionary psychology to understand the Star Wars saga!