Development and Validation of the Four-Item Mentalising Index ( FIMI )

RAC, LAL, and PS conceived the instrument, RAC, LAL, MJC, and PS collected and analysed the data, and all authors drafted, read, and approved the final version of the manuscript. The authors thank Zoe Freeman, Laura Smith, and Lois Player for acting as independent raters and/or assistance with data collection. RAC and ECT are supported by doctoral studentships from the Economic and Social Research Council and the Whorrod Foundation, respectively. All authors declare no conflict of interest.