Psychometric development and validation of victim gaslighting questionnaire (VGQ): across female sample from Pakistan
Authors: Bhatti Mahnoor Mahmood , Shuja Kanwar Hamza , Aqeel Muhammad , Bokhari Zainab , Gulzar Syeda Nasreen , Fatima Tabassum , Sama Manahil 
Published: December 2021

Purpose
Gaslighting a form of abusive manipulation both emotional and psychological is a growing phenomenon in recent times. However, as of yet, there is a scarcity of a valid and reliable instrument which can measure the severity of gaslighting in victims of interpersonal relationships abuse. The purpose of this study is the development of an instrument which can effectively measure gaslighting in victims and is psychometrically reliable and valid.

Design/methodology/approach
Since the aim of the study was the development of a scale first a sample of eight women who were victims of domestic abuse was taken for the focus group. Afterwards using purposive sampling a sample of 20 women for the pilot study and a sample of 150 women for the main study was taken with age range 18–40 (M = 23.38, S.D = 4.03). For the development of scale theoretical basis along with a focus group was conducted to establish an item pool. Afterwards, subject matter experts helped in establishing contend validity followed by Velicer’s minimum average partial (MAP) method and maximum likelihood factor analysis (FA) was performed for the establishment of the factorial structure of the instrument.

Findings
Velicer’s MAP method and Maximum Likelihood FA suggested two factor structures including peer disagreement and loss of self-trust. Instrument displayed high alpha reliability of α = 0.934, with α = 0.927 and α = 0.854, for the subscale, respectively.

Research limitations/implications
Though all necessary steps were taken to minimize the limitations of the present study, however, some limitations do exist which needs to be addressed. The foremost limitation of the present scale is that it is being developed with only a female sample, however, the inclusion of a male sample in future studies can help in identifying whether men also are victims of gaslighting from peers and other family members or not. The second limitation is of validity though necessary validities have been established future studies should study on establishing further validities to further refine the instrument. Additionally, the scale has only been validated and tested on female samples future studies should be conducted on other specific groups or samples to develop norms. Moreover, testing the scale on other cultures could also help in establishing cross cultural validation of the instrument. Finally, though the scale assumes a higher level of scores suggests a higher level of victimization, a proper cutoff score can help in further identifying proper victims from the normal level of gaslighting.

Practical implications
The present instrument has its applicability in several domains the most important being in the criminal justice system as gaslighting comes under gaslighting and even in the UK is considered as a criminal offense. This instrument can help in determining the severity of gaslighting in victims. Likewise, it can be used in clinical settings for psychologists to identify possible cases of gaslighting victims which can enable them to provide specific help and treatment for them. Moreover, researchers can also benefit from the instrument as it can enable them to explore gaslighting with other possible variables which can help them explore the concept of gaslighting even further.

Originality/value
This paper is a novel study and has been completed with the purpose of evaluating the effects of gaslighting in victims of interpersonal relationships abuse as the earlier measures are either not psychometrically valid or cannot be generalized to a wider population. The present established scale is an effort to construct an instrument that can be used worldwide.