New year, new paper! 4- and 5-year-olds can represent abstract relations (i.e., sameness and difference) predicated on an abstract dimension (i.e., kind membership) in a relational match-to-sample task. Moreover, noun label training facilitates task performance.

https://direct.mit.edu/opmi/article/doi/10.1162/opmi_a_00179/127437/Preschoolers-Represent-Abstract-Relations