Humans have at least 100,000 generations of evolution as hunter-gatherers, enduring feast and famine, acting as predators and hoping to avoid being prey. The legacy of that evolution is hardwired into our brains.

But our bent toward instant gratification — a key component of what helped us survive the environmental challenges of the Pleistocene — may well be our undoing in the Anthropocene. Even as environmentalists.

Our Lizard Brains: Just Not Interested in Tomorrow

We tend to think about instant gratification as a contemporary problem, with some of us wondering what social media and an everything-on-demand economy are doing to our ability to concentrate and plan for the future. But in his recent book “Misbehaving,” the behavioral economist Richard Thaler reminds us that the battle between fun today and paving the way for future success has been with us for millennia — captured well by Homer in his story of Odysseus and the Sirens.

But it is a battle. To describe it, Thaler and others have used the metaphor of two selves: “the doer and the planner,” or perhaps more memorably, the grasshopper and the ant in Aesop’s fables.

The doer seeks instant rewards; the planner has a longer range vision. Too often, it seems, the doer in us has the upper hand. We can trace this bias to the normal first-task-at-hand over our long evolutionary history: get all the food you need as fast as possible to stave off starvation and to avoid exposure to predators.

The fascinating thing about these two selves is that experiments have revealed how “cues” can make it next to impossible to take the long view. One classic experiment gave 4- and 5-year-old children the choice of ringing a bell and getting one Oreo cookie now, or — if they could wait a period of time— three Oreo cookies.

If the cookies were visible on a plate, kids typically lasted only a minute before ringing the bell and getting that instant reward (but losing out on the bigger, delayed cookie reward). Absent a plate of cookies in view, they lasted 11 minutes — and videos of the kids show even those 11 minutes were a struggle.

Lest you think this only applies to 4- and 5-year olds, a similar study was done with Princeton University undergraduate and graduate students, with not cookies but Amazon gift cards of different sizes. Unless the delayed gift card (awarded a month later) was more than 35% greater, the majority went for instant gratification.

The Princeton study added the twist of brain imaging the subjects during their decision-making, using MRIs. Several studies have suggested different brain centers corresponding to the doer and the planner: the prefrontal cortex “lights up” when higher abstract thinking and planning is engaged, while the limbic system (or “lizard brain”) lights up when some immediate reward is offered.

However, the Princeton study found that offering the instant reward caused the limbic system to light up, but the very same reward offered with a delay yielded no limbic activity. Our lizard brain just is not interested in tomorrow.

Environmentalism Needs to Acknowledge Its Own Lizard Brain

It’s obvious what these findings have to do with sustainability. Corporations, shareholders and investors increasingly demand immediate returns on investment, often to the detriment of the environment. The average duration for stock holdings on the NYSE was six years in 1975; by 2010 that had fallen to six months. There are many short-term investors who hold stocks for just a few days (or potentially even seconds).

Consumers also increasingly have fewer hurdles to instant gratification for a much wider range of goods than in the past — and in this case marketing and presentation provide cues that make it all that much harder to say “not now” (just as the plate of Oreo cookies in plain sight meant the kids could barely hold out for a minute).

You can hear the familiar refrain of environmentalists, complaining about all this. But we environmentalists have our own version of short-termism, our own struggles with our lizard brains that we fail to acknowledge. Too often our efforts focus on tomorrow’s court case, or the single impending road/dam/factory/development we want to halt. We seek dramatic symbolic statements now, or fight for dramatic singular victories tomorrow.

But what is our long-term vision for the world? What do we see for 2050, when there will be between 9 and 10 billion people?

For instance, will all rivers be free of dams — or do we have alternative plans for hydropower operations that might be compatible with people and conservation?

Can the locavore or organic movements substantively contribute to feeding 10 billion? What is our alternative if they can’t? How much seafood will come from aquaculture, and how much will be wild caught?

By 2050, three-quarters of the world will live in cities — what is our vision for those cities of the future, and is it a realistic vision given limited wealth and resources? And whom does that vision leave out, if anyone?

I am not denigrating battles against individual environmental issues. They have been the backbone of the environmental movement. But they do not, even in the aggregate, add up to a long-term vision of what we want the world to be — one that is more than just the word “no.”

We who care deeply about nature and the environment need to articulate what a prosperous and a healthy planet will look like in 2050, and work backwards from there. This will require a magical mix of inspired vision and cold hard analysis of biophysical constraints. But only that mix — plus a commitment to inclusiveness of different values and perspectives — can inspire others outside our tribe to join us.

Figuring out how to get to that 2050 is an important part of what we’re focusing on here at the Institute of the Environment and Sustainability at UCLA. If you have thoughts, we’d love to hear them.

Peter Kareiva is director of UCLA’s Institute of the Environment and Sustainability.


  • The Impulse Society. 2014. By Paul Roberts
  • Misbehaving. 2015. By Richard Thaler.
  • “Separate neural systems value immediate and delayed rewards” 2004. Science 306, 503-507. By S. McClure, D. Laibson, G. Loewenstein, and J. Cohen.