Over at Volokh Conspiracy, Illya Somin takes to heart Hal Finney’s suggestion that:

If you can make a case for progress even acknowledging that in the future your own practices may be seen as savage and appalling, you are much less likely to be manifesting self-satisfaction bias.

Ilya takes up the challenge:

I see at least three areas where there is a good chance of this happening: Animal Rights. … The Death Penalty. … Forced Labor. … If I am right about these predictions, should I revise any of my current moral views? … I am unmoved in my opposition to forced labor. … its increasing acceptance will say little about its rightness. I am less certain about the death penalty. … the fact that so many others are turning against it despite the lack of a clear self-interested or other biased reason for doing so does give me some pause. … I am least confident [regarding] animal rights. … My position is at least in part the result of a strong self-interested bias of my own: I like to eat meat. 

Hal similarly forecasts:

A more straightforward extrapolation to a future which is even more protective of powerless groups. Animal rights would expand; perhaps keeping pets will be seen as harmful oppression. … Children’s rights are another area of growth;

Commenting at Volokh Conspiracy, Friedrich Foresight quotes GK Chesterton (1904):

The way the prophets of the twentieth century went to work was this. They took something or other that was certainly going on in their time, and then said that it would go on more and more until something extraordinary happened.

Let me repeat my comment to Hal (endorsed by Eliezer):

The ability to substantially predict the future of morality would be a strong argument against morality changes being due to info we learn, just as the ability to predict future stock prices would argue against stock price changes being due to info. So you have to imagine a full range of possible future moralities, in all the imaginable directions, and then ask yourself if you would on average accept the future’s differing judgment, which ever way it went. If not, you don’t really believe that moral changes are mainly due to info.

Ilya and Hal both think they can forecast the same morality trends, but widely known long-term morality trends are not consistent with morality changes being mainly due to new info.  Communication delays might let a minority know about a trend for a short while, but the longer the trend and the more who know, the less this story works. 

This analysis applies to changes in music, clothes, work, mating, language, or pretty much any common behavior or attitude.  Info has no trend, so if you see trends, something besides info is at work.

If not info, what?  Wealth and lifespan have trended up.  Perhaps the morality of the old rich differs from that of the young poor.