The Development and Validation of the Successful Psychopathy Scale [Protocol]

The personality construct known as ‘Successful Psychopathy’ has attracted the interests of researchers and clinicians alike. The concept suggests an individual who demonstrates the core traits associated with psychopathy but is able to adapt and function within society to prototypical or superior standards. There has yet to be a sound theoretical model of this construct by which to base a psychometric measure. This protocol presents the ethical procedure that will endeavour to create such a measure and validate it within general population samples.


Duration of studies
Through the use of the participant crowdsourcing website Prolific (see 'Recruitment Methods'), enrolment and data collection of this study is estimated to take around 7 months to complete, due to administering the measure across three occasions to determine test-retest reliability. However, enrolment of the initial collection will remain open until the minimum sample (n = 400) is met, with additional data collected if necessary. The minimum sample size required was based on previous scale development research within a similar field (Caring Uncaring Emotional inventory, Semel, 2016) and the minimum sample required to conduct CTT. The duration of this study for each participant is expected to be no longer than 15 minutes at each timepoint.

Study Designs
This cross-sectional study will initially involve 400 participants completing a battery of questionnaires at a single timepoint. Demographics (i.e., age & sex), the newly developed Successful Psychopathy Scale (which will include items developed based on theoretical understanding of the construct, formulated from previous literature including a systematic review (Wallace et al., 2019) and expert ratings), and state measures of psychopathy, political skill, and expectancy for success. Responses to the Successful Psychopathy Scale only will be taken at two additional timepoints (3-6 months). Responses will be measured online using survey software Qualtrics.

Study Population, Selection Criteria, and Sample Size Justification
All participants will provide full informed consent, as indicated by a button press on the first and final pages of the survey. Participants will be males and females aged 18 years and over, of UK nationality, and fluent in English.
Sample size was derived based upon minimum and optimum sample sizes required to undergo Classical Test Theory or Exploratory Factor Analysis (CTT; EFA) and Rasch Analysis (Linacre, 1994/99;Tabachnick & Fidell, 2013).

Recruitment Methods
Participants will be identified through the crowdsourcing website Prolific (prolific.co), and the study survey will be made available to all members who meet the required inclusion criteria. This is an automated process determined through member responses to a series of questions answered when first signing up the platform. Prolific is thought to generate data quality comparable to that obtained by face-to-face means (Peer et al., 2017). Members who go on to participate in the study will be paid an average of £5 per hour; roughly £0.85 for this study (10 minutes). At the time of writing there are 33,469 potential participants to take part in this study, so data collection for this purpose is feasible.

Data Collection and Study Schedule
The initial survey will consist of the Successful Psychopathy Scale, plus a battery of questionnaires, which will be collected at one timepoint. On the first two pages of the survey, participants will be presented with all study information and will be asked to affirm their consent. On subsequent pages (not accessible unless consent has been given), participants will be asked to answer brief demographic questions (i.e., age, sex) prior to completing five psychometric measures, namely the Successful Psychopathy Scale  , 2005). Each scale will be presented, along with completion instructions, on a separate page, and the study will close with a debrief page where participants will be asked to re-affirm their consent. Two additional timepoints will be collected for the Successful Psychopathy Scale at 3-and 6-month intervals. Data will be maintained for as long as necessary (with identifiable data destroyed after two weeks from each timepoint) for the purpose of transparent and open science, with the exception of data obtained from participants who withdraw from the study either during or following participation (up to a period of two weeks). In such cases, any associated data will be permanently deleted.

Expected Outcomes
The research team expects the Successful Psychopathy Scale to hold a similar theoretical structure to the initial conceptualisation of psychopathy as derived by Cleckley (1955Cleckley ( /2016. Moreover, as existing literature suggests, it is expected that the Successful Psychopathy Scale will be positively associated with self-reported boldness (Persson & Lilienfeld, 2019), meanness (Persson & Lilienfeld, 2019), political skill (Lilienfeld et al, 2012). Furthermore, it is theorised that successful psychopathy will be positively associated with an expectancy of success within professional domains (e.g., status and wealth) and be negatively associated with disinhibition and expectancy of success in personal domains (e.g., family).

Ethical considerations
Participants will provide consent and will be debriefed following the study. There is no expectation of any adverse outcomes or effects on participants as a direct result of this study. Nevertheless, the research team acknowledges that questions asked within this study relate to personality, which may lead participants to ruminate on their wellbeing. As such, participants will be signposted to UK-based mental health charities (e.g., MIND) and their healthcare providers (e.g., general practitioners) at both the point of consent and the debrief. Participants are neither asked nor expected to disclose any subsequent correspondence with such services to the research team.

Reasons for Withdrawal
Potential participants identified via Prolific are under no obligation to take part in the study. Participants who do consent to take part can withdraw their consent either during the study (by closing their web browser or by not affirming consent at the point of debrief) or after taking part in the study up to two weeks prior (by e-mailing the Principal Investigator (PI) using the provided e-mail address with their Prolific ID, an ID associated with their specific data entry). No reason for this withdrawal will be asked or expected to be given. Participation in the study may be automatically terminated (via Qualtrics settings) should the participant decline to give consent. No adverse events will be measurable during the study due to the data being collected remotely and not in person. As such, no considerations are made for adverse events that lead to participant termination up to two weeks following participation.

Handling of Participant Withdrawal
As mentioned above, participants may withdraw at any time during the study and up to two weeks afterwards, and participants will not be asked to give a reason for their withdrawal. Participants who withdraw from the study will be replaced, and in such instances, further participants will be sampled to ensure the study sample does not fall under the optimal number.

Premature Termination or Suspension of Study
Although not expected, the study may be temporarily suspended or prematurely terminated if there is sufficient and reasonable cause to do so. In such instances, the PI will directly notify the research ethics committee that approved the study in writing, providing reason(s) for the suspension and/or termination of the study. Potential circumstances which might result in temporary suspension or premature termination include [1] unexpected, significant, or unacceptable risk to participants, [2] determination of futility, and [3] unexpected detriment to the secure maintenance and quality of data. The study may resume once any concerns have been addressed and satisfy the needs of both the research team and research ethics committee.
found with CTT, for example using Differential Item Functioning (DIF) to determine non-consistent responses across a trait and identify candidates for removal from a scale. Additionally, Rasch allows precise measurements of individuals at the extremes of a scale (Hobart & Cano, 2009) which is particularly relevant when assessing Successful Psychopathy where the research team are interested in those extreme scores.
To determine concurrent and convergent validity of the scale Pearson's correlations and linear regressions will be conducted between each variable.

Assessment of Safety
Although not expected, this study will follow standard definitions of adverse events (AEs) and report any AEs to the research ethics committee for up to two weeks after the final participant has taken part in the study.

Adverse Events
Defined as any unanticipated physical or mental well-being occurrence, regardless of its relationship to the study, such as self-reported stress or anxiety following participation in the study that may or may not require further intervention.

Serious Adverse Events
Defined as AEs that are considered serious, such as those requiring hospitalisation, are life-threatening, or result in death.
In the event of any AE being acknowledged by the research team, the PI will assign a level of severity to the event (Mild, Moderate, Severe) and assess the likelihood that said AE is related to the study protocols (Definitely, Probably, Possibly, Unrelated). These categories are further delineated in Table 1. The relationship between the AE and the study protocol cannot be clearly established, but the definite lack of a relationship cannot be concluded Unrelated There is no relationship between the AE and the study protocol.

Data Monitoring
The PI will be responsible to ensure the study is conducted in accordance with the protocol, standards of Good Clinical Practice (GCP), and applicable regulatory requirements as defined by the British Psychological Society (BPS), and that the data recorded is valid and appropriately stored and maintained. To this end, data collection (via Prolific) will be collected in three stages to ensure quality: Stage 1 being a short pilot of five participants to check data quality and difficulties arising from the usability of the questionnaire, and Stages 2 and 3 being the collection of male and female responses separately to ensure a good distribution of data across sexes. The questionnaire pack is devised in a manner to minimise errors (e.g., clear instructions) and uses a 'request response' function in order to remind participants to complete all sections of the survey should any question be missed. To comply with ethical standards, although this function is enabled, participants will be able to subsequently skip said item should they not wish to complete it.
No external data monitor will be appointed to ensure the study complies with GCP or BPS standards. Data and analysis scripts will be made available on request.

Data Handling and Record Keeping
The collection of personal data from the participants will be limited to the number and type required to perform the planned analyses and in order to achieve the aims of the research. Data will be maintained on Qualtrics (survey software and secure database) until the required sample size has been collected, at which point the data will be exported into an Excel or SPSS file format (password protected), backed-up, and subsequently deleted from Qualtrics. Any unique identifiers collected within the dataset will be permanently deleted two weeks after the final participant completes the study, and there will be no hard copies of the data The Journal of Concurrent Disorders, 2021 8 generated or maintained. Fully anonymised data will be used for data analysis, which will be led by the PI (LW).

Research Ethics Committee
The protocol, participant-facing documents, and questionnaire pack will be submitted to a local research ethics committee for review, feedback, and approval. Approval of all documents is required before any participant enters into the study. Any amendment to the protocol will undergo further review and approval by the research ethics committee before the changes are implemented to the study; however, as participation is anonymous and participants are not requested to provide contact details, re-consent to take part in the study will not be possible, and as such any data obtained prior to amendments will only be treated in accordance with the elements and procedures for which consent was given.

Consent Process
After clicking on the study link and being presented with the study information sheet (including all information about the study, methods of withdrawal, information about data management, and contact details of the study team and signposted services), participants will then be presented with the consent form on the subsequent page of the online survey. To take part in the study, participants must affirm their consent and understanding of the aforementioned information via a button press; refusal to do this will lead the Qualtrics software to terminate their participation with a 'thank you' message. Participants will also be shown an optional consent box for the test-retest follow ups at 3 and 6 months, this is not mandatory and selecting 'I do not consent to take part in the follow-up survey' will allow them to complete the initial questionnaire with no expectation to take part in any of the subsequent surveys. Participants will not have to sign, date, or present any additional identifiable information. Following a debrief of the study, and in accordance with guidelines for internet mediated research (BPS, 2017), participants will be asked to re-affirm their consent as a means of mitigating against the usage of data from participants who prematurely exited the study and/or those who no longer wish for their data to be used after completing the study.

Protocol Deviation
Protocol deviations are defined as any deviation from the ethically approved study protocol and can be attributed to either the research team or study participants. However, as the nature of the study makes it improbable that participants could generate protocol deviations, a research team-related example of a protocol deviation for this study might include the use and storage of data in an unapproved manner. Any protocol deviation will be made aware to the research team at the earliest availability and corrective measures will be actioned if appropriate. Causes, actions, and results of any protocol deviations will be signalled to the research ethics committee in writing at the first available opportunity.

Publication and Data Sharing Policy
It is the intention of the research team to publish any and all findings of this study in written (e.g., posters, journal publications, blog posts) and verbal (e.g., conference paper) form. The research team might also use findings of this study as a base for future research submissions and/or grant applications. At all stages, individual participant responses and associating identifiable information will be kept confidential, and only group-level analyses will be presented/published. In accordance with emerging trends in open science, anonymised raw data and pre-print manuscripts will be made openly available. Table 2 documents the members of the research team and their associated responsibilities throughout the duration of the project.