I have an hypothesis I would love to test and it is this:
You can tell the date that a GUI designer bought their first HiFi
by the level of gaudiness of the GUI - X Windows for example had a number
of toolkits and look and feel/skins like Motif and Athena Widgets, which reminded me a lot of the late 70s and early 80s design of Amps with lots of knobs and sticky out stuff and shiny brushed aluminium, and then later, with matt black and minimal
exterior stuff, whereas tcl/tk's toolkit first look and feel was more the colloidal/organic feel of late 80s early 90s, even Bang & Olufsen....
Also, you can tell a lot about a person from the state of their home directory - some people organise it with docs, bin, lib, Mail, Arc, Tmp (a bit like / on a unix box)
but some people have a zillion random files called foo bar baz big, tmp, and 044333xxx.arc etc - usually (but not always) this is mirrored in the physical state of their desk/office, but does it reflect their thinking too? I think we should be told...