I have a file with content akin to the following (which will be the base of my MWE) with the result shown:

Here's the MWE:
\documentclass{article}
\usepackage{booktabs}
\begin{document}
\begin{tabular}{c c@{\hspace{0.5em}}c}
Item & \multicolumn{2}{c}{Type} \\
\midrule
Thing 1 & babel & bottle \\
Thing 2 & cable & cattle \\
Thing 3 & fable & fiddle \\
\end{tabular}
\end{document}
This is exactly what I want. Unexpectedly, when I changed "Type" to something wider than the second and third columns, I obtained this result:

I expected the width between the second and third columns to remain the same, and that both would be centered under the header "Representations". I played around with a number of things, but I could not achieve that result.

