After clambering in and out of all the vintage trains at the Ulster Transport Museum, my kids always want to stop by the museum’s exhibition on the Titanic, which was built in Belfast’s shipyards. At the center is a model of the vessel, surrounded by groups of figures representing the survivors and those who lost their lives when the ship sank, all grouped by passenger class.

“Nothing shows the entrenched social gradient that traveled with the Titanic’s passengers more than the statistics on deaths after the ship sank: just a quarter of third-class passengers survived compared with 62% of those in first class,” says Newcastle University’s Niall Cunningham.

He gives this Titanic example in his discussion of a recent study that uses U.S. cellphone data to measure social interactions in public spaces. It shows businesses like casual chain restaurants – Olive Garden and Applebee’s, for our U.S. readers – tend to attract all kinds of people. This suggests a greater possibility of interactions across class lines at these eateries than in other public spaces.

If mobiles had been around in 1912, Cunningham argues, the data generated by the Titanic’s passengers would have suggested it was “a sort of utopia for social interaction.” But in reality, as the Ulster Transport Museum’s exhibit shows, the ship’s passengers travelled according to class and probably had very little to do with each other.

And since phone location data is a blunt tool when measuring social interaction, Cunningham’s guess is that the people eating at Olive Garden aren’t mixing much, either.