Part of Hindsight 2070: We asked 15 experts, “What do we do now that will be considered unthinkable in 50 years?” Here’s what they told us.

Peter Singer is Professor of Bioethics at Princeton University, and the founder of The Life You Can Save, an organization that recommends the most highly effective charities. His books include Practical Ethics, The Most Good You Can Do, and Ethics in the Real World.

So you paid $60,000 for your Patek Philippe watch, reminding yourself that you never actually own one of these timepieces; you merely look after it for the next generation. Well, I have news for you: The next generation isn’t going to want those clunky mechanical things that don’t keep time as well as their trim digital devices, which, for about one-thousandth of the price, do so much more.

Better technology is here, of course, and yet people still buy absurdly expensive mechanical watches, because they are status symbols. I’m predicting that this too will be undermined, not by better technology but by better taste. The ostentatious display of wealth, in a world that still has many people in need, is not in good taste. Within 50 years, we’ll wonder how people did not see that.

We might, of course, eliminate extreme poverty in less than 50 years. I hope we do, and the progress we have made over the past 50 years has been encouraging. Still, with the problems we’re causing for the future by our reckless emission of greenhouse gases, and the rapid population growth occurring now in some of the world’s poorest countries, it is hard to imagine that there won’t be better things to do with your money than use it to display how rich you are.

Is it naive to suggest that rich people will cease to display their wealth? After all, it is 120 years since Thorstein Veblen, in his classic Theory of the Leisure Class, coined the phrase “conspicuous consumption.” Yet conspicuous consumption is as widespread as ever. It starts with people wearing clothing that displays a brand name conveying the fact that the item cost far more than equivalent items without that brand, while at the other end of the scale, it runs to oceangoing “yachts” that cost hundreds of millions of dollars and use more fuel in an hour than a small car would use in 10 years. What will make it socially unacceptable?

My prediction rests on the belief that we are slowly making moral progress. Over the long term, our circle of concern has expanded from the tribe to the nation, and from the nation to humans everywhere. Now it is extending, though far too slowly, to nonhuman animals.

The effective altruism movement, built by millennials, is part of this trend toward living more ethically. Effective altruists aim to do the most good they can. They use reason and evidence to find out how to do that. Many of my students at Princeton are choosing careers that will give their lives meaning rather than wealth. If they make money, they will look for something worthwhile to do with it. For many of them, that means an effective nonprofit organization working to help people in extreme poverty, combat climate change, or fight factory farming.

Although millennials often have the reputation of being narcissistic, that rests on little more than the fact that they post selfies on social media. If earlier generations had had the ability to do that, they would probably have done the same. More significant are studies that show that millennials are not only generous but also much more thoughtful in their generosity than older generations, going to more trouble to find out what impact a charity has before they donate to it.

Psychological research suggests that these students are making a wise choice. Acquiring new toys or trinkets provides a temporary buzz, but soon we adapt to our new possessions and, in terms of happiness, are back where we started. That puts us on a hedonic treadmill, working harder to earn more to buy more to maintain the same level of satisfaction. In contrast, when researchers give people money and tell them to spend it on themselves, the recipients rate their day less favorably than those who are given the same sum and told to buy something for someone else.

We won’t get this wrong forever. Eventually we will learn what makes us happy and makes the world a better place. I give it 50 years.