Particularly in forensic contexts, children who are victims or witnesses of crimes are heard as witnesses. Judicial practice highlights how they are often heard multiple times by police, professional figures, and judges. If children are already exposed to several suggestive interviews before giving their official testimony in court, it becomes important to clarify what effect repeated exposure to suggestive questions has, not only in terms of altering recollection but especially in terms of vulnerability.

The main aims of the present study are to verify whether repeated suggestive interviews lead to an increase or decrease in children’s level of suggestibility and resistant responses (Gudjonsson et al. 2021) and how age and intelligence quotient can reduce their vulnerability.

Several studies have shown how exposure to misinformation and leading questions can lead to memory impairment (Loftus 1979; Loftus et al. 1990; Lamb et al. 2008). Furthermore, the literature highlights that suggestibility is one of the principal risk factors for eyewitnesses and that immediate and delayed suggestibility are different and independent: the first concerns the way in which the individual answers the leading questions, while the second represents the tendency to incorporate misleading information into the original memory (Vagni et al. 2015; Gabbert and Hope 2018; Gudjonsson 2018).

Lamb and colleagues (Lamb et al. 2008) have shown that 80% of the questions that are addressed to children during forensic hearings are closed and require dichotomous yes/no or more alternative answers. The children’s ability to distinguish different responses and, above all, their effectiveness in rejecting both immediately—in the case of exposure to factors of repetition of suggestive questions and factors of emotional pressure, and, after time, the suggestions to which they may be exposed—represents a critical aspect of their accuracy and testimonial reliability.

According to several authors, children have less ability to source monitoring and trust in their own memory, leading to the risk of them confusing information suggestively provided and actually experienced, altering their original memory (Nelson and Fivush 2004; Bauer and Larkina 2016; Jack et al. 2016). Moreover, children in the forensic context are more affected by expectations of success, interpersonal trust, and authority of figures such as policemen or judges and are more vulnerable to emotional and social pressures (Vagni et al. 2018). It seems important to understand if and how these aspects can reduce the reliability of children’s memories when they are victims and witnesses of some crimes.

Few studies, however, seem to have considered what effect this produces in children in terms of their ability to respond to subsequent suggestive questions (Melnyk and Bruck 2004).

To better understand what the effects of repeated exposure to suggestive questions may be, it is first necessary to explain what is meant by interrogative suggestibility and resistant responses.

The paradigm of interrogative suggestibility (IS), also called immediate suggestibility, developed by Gudjonsson and Clark (1986), is a psychosocial model that refers to the social pressure that an interviewee receives during the process of answering suggestive questions.

The model of Gudjonsson and Clark (1986), which is used primarily in the forensic context, includes two distinctive and independent aspects of interrogative suggestibility: the impact of “leading questions” and “negative feedback” (Gudjonsson 2003). The “leading questions” are questions that contain suggestions to influence the response of the interviewee or witness through post-event information or misleading information. The negative feedback is a criticism directed at respondents to increase their degree of uncertainty and insecurity.

The main assumptions of IS are uncertainty, interpersonal trust, and expectations of success. Leading questions include misleading information, and this leads people to be uncertain about the correct answer. This occurs all the more when the suggestive information appears pertinent, plausible, and compatible with one’s knowledge and expectations. Interpersonal trust means that the witness believes that the interviewer’s intentions are true. Expectations of success indicate the belief of the witness that they are able to answer the questions correctly.

According to the IS model, there are two factors of suggestibility: yielding, which is the tendency to accept leading questions (Yield), and Shift, which is the tendency to change one’s answers following negative feedback (Gudjonsson 1984, 1987).

Previous studies indicated a strong negative relationship between intellectual ability and interrogative suggestibility (Gudjonsson 1983, 1990, 2018), and Frumkin et al. (2012) found intellectual ability to be more closely related to the tendency to yield to misleading questions than the tendency to shift answers following negative feedback.

In addition, regarding cognitive factors, age influences the level of suggestibility, given its relationship with developmental processes (Caso et al. 2013; Goodman et al. 2014). Several studies have shown that younger children are generally significantly more vulnerable to misleading questions (Ceci et al. 2007; Goodman et al. 2014), and this may be due to their poorer memory traces (Ceci 1994; Goodman 1984), lower language skills and less developed cognitive abilities than older children (Eysenck 2015).

Furthermore, according to Ceci and Bruck (2006), younger children are probably more influenced by social pressure and lack of social support. In relation to immediate suggestibility, age seems to have an impact on up to 12 years of age; subsequently, the performance of children over the age of 12 is similar to that of adults (Gudjonsson 2003).

Age appears to be a significant predictor of immediate suggestibility but not of delayed suggestibility (Lee 2004).

With regard to socioemotional factors, exposure to adverse life events, including being involved in court cases as witness, appears to correlate with higher levels of suggestibility (Drake 2010, 2011, 2014; Drake et al. 2008; Gudjonsson et al. 2020; Vagni et al. 2021), and reduces the ability to cope with interrogative pressure (shift) and repeated questioning (yield 2) (Drake 2014; Vagni et al. 2018, 2021).

Recent studies (Gudjonsson et al. 2021, 2022) highlighted the importance of also considering how children respond to suggestive questions and what resistant responses they can express.

People have several ways to answer leading questions: accepting, rejecting, or admitting they do not know the answer. The different responses of refusal of a suggestion represent the Resistant Behavioural Responses.

The Resistant Behavioural Responses (RBR) is a model validated by (Gudjonsson et al. 2021, 2022) and is based on a source monitoring framework (SMF; Johnson 1997; Johnson et al. 1993; Johnson and Raye 1981) that “refers to a set of processes involved in making attributions about the origin of memory, knowledge, and beliefs” (Johnson et al. 1993, p. 3). People can answer leading questions by accepting, refusing with a simple “No” (NO answers), or expressing one’s uncertainty (“Don’t know”, DK answers). People who have high source monitoring of information respond by providing direct E\explanations (DE answers) and not just saying no. Many studies are concerned with “Don’t Know”-type answers (DK), such as RBR in children (e.g., Brubacher et al. 2015; Earhart et al. 2014; McWilliams et al. 2014; Waterman and Blades 2011), highlighting how younger children have difficult answering “don’t know” and declaring their uncertainty, probably due to their poorer understanding of unanswerable questions and greater expectation that they must provide either ‘yes’ or ‘no’ answers (Ceci and Bruck 1993).

A recent study on 360 children aged between 7 and 17 years (Gudjonsson et al. 2022) found that NO, DE, and DK answers are different and independent response styles that have different effects on resistance to misleading questions. In particular, “Direct Explanation” answers are the most stable and robust and increase incrementally with age in children (Gudjonsson et al. 2021). The results showed that DE answers are driven by different cognitive and social processes than DK and NO answers. The main difference between DE, DK, and NO answers is that for DE answers, people recognize the discrepancy between what was observed, showing effective strategic source monitoring and control processes.

For the purposes of the study, it is important to detect what the effects of repeated suggestive questions could be in terms of the degree of vulnerability and the ability to resist suggestibility.

The effect of repeated suggestive questions over time has been investigated by other previous research, sometimes leading to conflicting results. Some studies found that repeated interviews can help support accurate memory (Goodman and Quas 2008; Hershkowitz et al. 2021) and may be helpful for building rapport with children (Faller 2014). However, excessive interviewing of children using suggestive techniques can be detrimental to accuracy (e.g., Ceci et al. 2007), especially if memory is weak for what occurred (Goodman and Quas 2008). Children are more likely to change their answers (e.g., to “I don’t know”) to repeated yes/no, forced-choice, or suggestive questions, or to challenges to their original answers (Candel et al. 2000).

Warren and Lane (1995) showed that the repetition of more suggestive interviews did not necessarily lead children to be more suggestible. Cassel et al. (1996) found that the tendency to yield to repeated-ended suggestive questions decreased with age leading 12-year-olds to perform similarly to adults and display stable levels of suggestibility (La Rooy et al. 2009). In answering repeated leading questions, various factors intervene, such as age (Gudjonsson 2003; Gudjonsson et al. 2016); higher source monitoring skills (Lee and Shin 2022); coping strategies (Maiorano and Vagni 2020; Rossi-Arnaud et al. 2023); language skills; stressful nature of the context, such as the forensic one (Vagni et al. 2018); and resilience skills (Gudjonsson et al. 2020; Gudjonsson et al. 2021). However, inter-subject variability in levels of vulnerability depends on individual differences (Klemfuss and Olaguez 2020).

With increasing age, children develop greater cognitive skills that allow them to better cope with the repetition of suggestive questions and the possible confusion effect deriving from misleading information and perceived social pressure during the interview.

According to Memon and Vartoukian (1996), children who were able to answer “Don’t know” and understood that this answer was plausible and accepted by the interviewer in subsequent interviews were more resistant.

Learning that a resistant answer is effective may lead children to use it more in subsequent interviews. People who have certain skills, such as memory confidence, metacognitive skills, ability to monitor sources, and critical analysis skills, are less suggestible and less influenced by context (Johnson and Raye 1981; Parker and Fischhoff 2005; Singh and Gudjonsson 1992). Often, these skills are not present in younger children because they require greater cognitive maturity.

Previous studies have verified the effect of repetitions of misleading questions using the same questions at a distance of time or creating similar interviews. Few studies have used the repetition of two parallel scales with the same psychometric properties that guarantee measurable and comparable results (Baxter and Bain 2002). The existing literature lacks a study that has measured what children’s effective resistance capacities may be when, over time, they are subjected to multiple suggestive interviews presenting misleading information. Indeed, no study has associated the effect of repetition of suggestive interviews in children with the Resistant Behavioral Responses model to test whether capacities of resistance vary or remain stable.