Interview Statement
Unreliability Characteristic
Vocal Characteristics
Q1. Where do you have pain?
A1. Er, umm, all over – most of the time, especially when I bend down.
1. Speech hesitations: use of words ‘ah’, ‘um’, ‘er’ and so on.
Q19. Did you go to see your GP straight away?
A19. No, the next day, or maybe three days later – I can’t be sure.
2. Latency period: period of silence between question and answer.
3. Speech errors: word and/or sentence repetition, sentence change, sentence incompletions, slips of the tongue, and so on.
Q7. Have you ever had any psychological care or advice before this accident at work?
A7. (Look away before answering, then answer without looking at X). Five second pause. No I don’t think so, it’s hard to answer.
Facial Characteristics
4. Gaze: avoiding the face of the conversation partner.
Q9. Excuse me asking, but have you ever had any problems with the police?
A9. (Shifting in chair, move legs). No, not really – nothing serious. (Blinking three times in rapid succession).
5. Blinking: Blinking of the eyes.
Q11. If I had met you just before this accident at work, how were you feeling?
A11. (Scratching her head a lot; pausing) just after the accident?
Q12. No, just before.
A12. I was ok. (Pause). I had been a bit nervous and down at work and my GP had given me some antidepressant tablets – I think it was then, or it might have been a couple of months before – I can’t remember.
Movements
6. Self-manipulations: scratching the head.
Q7. Have you ever had any psychological care or advice before this accident at work?
A7. (Look away before answering, then answer without looking at X). Five second pause. No I don’t think so, it’s hard to answer.
7. Shifting position: movements made to change the sitting position (usually accompanied by trunk and foot/leg movements). Frequent non-verbal indications of discomfort.

Figure 1: Example of unreliable non-verbal behaviour

General Characteristics
General Characteristics of Reliability and Truthfulness
Q16: Was the ward busy that day?
A16: I remember it was. We had had an inspection and everyone was trying to keep up the ward clean and tidy – the ward sister had asked for the floor to be washed a second time.
1. Logical structure
2.Unstructured production
3. Quantity of details
Specific Content
Q14: I understand you slipped on a wet hospital floor?
A14: Something like that, there was lots of rubbish on the ward. I remember the floors had been washed that morning.
4. Unexpected complications during the incident
5. Unusual details
6. Superfluous details
Q17: Did you lose consciousness when you fell over?
A17: I think so, I was in shock – I was worried I was seriously injured.
7. Accounts of subjective mental state
Q24: How long did you have off work?
A24: About six months. I returned to work on my birthday, six months later. I remember because several staff gave me cards.
8. Contextual embedding
Q26: Dr Jones’ medical report says you were off work for four months.
A26: I was, but when I went back, after 2 hours I couldn’t cope with back pain and dizziness and had another 2 months off.
9. Descriptions of interactions
10. Reproduction of conversation

Figure 2: Interview Statements

Interview Statements
Psychological Characteristics of Unreliability
Q18. When it was happening did you think you were going to be severely injured?
A18. Oh yes, after I got up, a nurse said I was lucky not to be paralysed. I think I had stress and depression. (No emotion shown).
1. Inappropriateness of language and knowledge
2. Inappropriateness of affect
Q20. Did you see your GP again? Did anyone suggest you go?
A20. Sorry, I’m not sure. Yes about two weeks later I think – not sure. Yes, my brother suggested this would be a good idea.
3. Questionable motives to report
Q21. Did your GP suggest any treatment?
A21. Oh yes, we talked about it – I got given some tablets. I wasn’t there long, he’s always very busy. I do remember him saying he had a fall in his surgery. My brother who is a psychologist, suggested I have counselling.
4. Questionable context of the original disclosure or report
Q22. Over the next few weeks, did you have problems sleeping?
A22. Yes, I had nightmares every night, always about this awful accident and sleeping. I also had flashbacks a lot, remembering what happened very vividly. My partner thought I had PTSD. I still have nightmares almost every night.

5. Pressures to report falsely (e.g. avoid detection; obtain compensation)
6. Inconsistency with the laws of nature

Q26. Dr Jones’ medical report says you said you were off work for four months?
Q26. I was, but when I went back, after two hours I couldn’t cope with my back and had another two months off.
7. Inconsistency with other statements.
Q30. How is walking confidence now, twelve months on?
A30. A little better, but I notice in crowded situations or wet surfaces I am still nervous.
8. Susceptibility to suggestion
Q33. Reading your GP notes I see you had several prescriptions for antidepressants and sedatives in 2010, 2012, 2013 and 2015?
A33. I’d forgotten about this.
Q34. Post-accident, there is no reference to the work accident in GP attendance and no extra medication prescribed, just previous sedatives.
A34. It is difficult to remember all this.
9. Inconsistency with other evidence.

Figure 3: Psychological Characteristics of Unreliability