The presidents of Dartmouth College and Stanford University have sent a joint letter to apologize to about 100,000 Montana citizens after three of the schools’ political science professors conducted an unethical experiment involving the state’s voters.

The voters received letters providing political information about candidates running in the state’s Supreme Court election that were marked with the official state seal. But they actually came from the three professors who were studying whether the mail would affect voting patterns. Similar mail was sent to voters in California and New Hampshire.

According to a Stanford spokesperson, no institutional review board at Stanford approved the experiment, although a board at Dartmouth may have approved an earlier version of it.

Montana officials have accused the researchers of violating four laws, and the professors have remained silent. However, the universities’ apology letter clearly states that no experiment should ever risk altering an election’s outcome.

Still, some critics have questioned the apology’s sincerity, noting that one of the accused professors previously conducted a controversial experiment that examined legislator-constituent relations by sending Texas lawmakers more than 1,000 emails that appeared to come from voters.

We urge all those in the social sciences to remember that the world is not a laboratory. Experiments often have real-world consequences that sometimes outweigh the benefits of scientific knowledge. Ethical codes are the only thing protecting people from being studied unwittingly.