1. The mechanical repetition of previously received ideas or images that reflects neither true reasoning nor feeling.
2. Repetition of words or phrases parrot-fashion, without reflection, automatically.
From French, psittacisme; German, psittazismus - parrot.
Seen (first and latest example)
1896 A. G. Langley tr. Leibnitz' New Ess. conc. Hum. Und. ii. xxi. 196
All that they do think about it [sc. the future life] is but a psittacism, or gross and vain images after the Mahometan fashion, in which they themselves see little likelihood.
1975 Jrnl. Roman Stud. LXV. 187
Military matters are also the subjects of contributions from two younger British scholars, which are remarkable not least for being unencumbered by the needlessly repetitive anthologies of modern literature, a healthy immunity from that pernicious psittacism too widespread in this volume.
One of my favourite clothing designers, Scott Jordan, occasionally makes a political comment or complaint on his Twitter, and this is often followed by one of his other followers - let's call him 'John' - who often tells Scott to watch his language and keep his opinions to himself (swearing and personal opinion, on the internet!?) and often cites the phrase 'ad hominem' in his request, typically when Scott comments on how much he dislikes some of the right-wing nutbags. The funny part is, however, that 'John' often commits this psittacism without really understanding how argumentum ad hominem actually works, proving himself to be a psittacist.