Problem gambling in early adulthood: a population-based study

The aims of this study were to investigate stability of problem gambling between 20 and 24 years of age, and the antecedents and consequences of problem gambling at age 20 years. Young adult participants in the Avon Longitudinal Study of Parents and Children (ALSPAC) completed computer-administered gambling surveys on paper, or online. Responses to the Problem Gambling Severity Index (PGSI) were complete for 2624 participants at 20 years, and 1921 participants at 24 years. Responses were categorized into ‘non-problem’ (71–78%), ‘low-risk gambling’ (16–21%), ‘moderate-risk gambling’ (4–5.5%), and ‘problem gambling’ (1–1.5%). The overall frequency of moderate-risk/problem gambling varied little between age 20 and 24 years, and scratch cards, online betting and gambling were the most frequent activities. Problem gamblers at age 20 years had a history of hyperactivity and conduct problems in adolescence, high sensation seeking, and an external locus of control. They were more likely to have mothers who had problems with gambling, reported less parental supervision, and higher social media usage. Moderate-risk/problem gambling at age 20 years was associated with regular cigarette smoking, high levels of illicit drug use, and problematic use of alcohol at age 24 years. A significant minority of young adults (mainly males) showed problem gambling behaviours which appeared to be established by the age of 20 years and were associated with other potentially addictive behaviours

Gambling in young adults aged 17-24 years: a population-based study

A large contemporary UK cohort study, the Avon Longitudinal Study of Parents and Children, was used to investigate gambling behavior and to explore the antecedents of regular gambling in the 17–24-year age group. Participants completed computer-administered gambling surveys in research clinics, on paper, and online. The sample sizes were 3566 at age 17 years, 3940 at 20 years, and 3841 at 24 years; only 1672 completed all three surveys. Participation in gambling in the last year was reported by 54% of 17-year-olds, rising to 68% at 20 years, and 66% at 24 years, with little overall variance. Regular (weekly) gambling showed a strong gender effect, increasing among young men from 13% at 17 years to 18% at 20 years, and 17% at 24 years. Although gambling frequency increased between the ages of 17 and 20 years, gambling behaviors showed little variance between 20 and 24 years, except online gambling and betting on horseraces. The commonest forms of gambling were playing scratchcards, playing the lottery, and private betting with friends. Gambling on activities via the internet increased markedly between 17 and 24 years, especially among males. In the fully adjusted model, individual antecedents of regular gambling were being male, and having a low IQ, an external locus of control, and high sensation seeking scores. Parental gambling behavior and maternal educational background were associated with regular gambling in both sexes. Regular gambling was associated with smoking cigarettes and frequent and harmful use of alcohol, but no associations with depression were found

Meerkat close calls encode group-specific signatures, but receivers fail to discriminate

A great deal of variation is known to underlie the vocalisations of animals. Calls can for example vary among individuals or between social and behavioural contexts. Calls also have the potential to vary between groups. Many group living animals are known to produce stereotyped group-specific calls and such group signatures are thought to play a role in territory defence or indeed mate choice. Group signatures are generally found in long-distance call variants that work to maintain contact between group members, sometimes referred to as “contact calls”. Cooperatively breeding, territorial meerkats (Suricata suricatta) also use contact calls, potentially to maintain social organization during foraging. However, these contact calls are generally quieter, than long distance calls in other species, and better described as “close calls”. We investigated whether these similar call types also possess group-specific signatures and whether any such variation is used by receivers. We recorded close calls from 71 individuals belonging to 10 different meerkat groups. We found that such close calls do indeed possess group signatures, but that this underlying variation does not appear to be used by receivers, possibly because meerkats use other sensory systems to identify non-group members. We stress the importance of conducting playback experiments when investigating group-specific vocal signatures and use our results as a basis for predicting which animals may rely on group information encoded within close calls

Expression of emotional arousal in two different piglet call types

Humans as well as many animal species reveal their emotional state in their voice. Vocal features show strikingly similar correlation patterns with emotional states across mammalian species, suggesting that the vocal expression of emotion follows highly conserved signalling rules. To fully understand the principles of emotional signalling in mammals it is, however, necessary to also account for any inconsistencies in the way that they are acoustically encoded. Here we investigate whether the expression of emotions differs between call types produced by the same species. We compare the acoustic structure of two common piglet calls—the scream (a distress call) and the grunt (a contact call)—across three levels of arousal in a negative situation. We find that while the central frequency of calls increases with arousal in both call types, the amplitude and tonal quality (harmonic-to-noise ratio) show contrasting patterns: as arousal increased, the intensity also increased in screams, but not in grunts, while the harmonicity increased in screams but decreased in grunts. Our results suggest that the expression of arousal depends on the function and acoustic specificity of the call type. The fact that more vocal features varied with arousal in scream calls than in grunts is consistent with the idea that distress calls have evolved to convey information about emotional arousal

Development of Alarm-Call Production, Usage and Responses in Meerkats (Suricata suricatta)

Despite strong selection on young and adult prey to avoid predators, we often find obvious differences in anti-predator behaviour between them. By examining the ontogeny of antipredator behaviour, we can gain insight into how young animals come to classify predators, knowledge crucial for their survival. In this thesis, I investigated how and when young meerkats (Suricata suricatta) develop the ability to produce alarm calls with an adult-like structure, how they come to use these alarm calls in appropriate contexts, and how they respond to the alarm calls of other group members. Meerkats, which are cooperatively breeding mongooses living under a high predation pressure, have evolved a sophisticated alarm-call system consisting of calls which simultaneously encode information about specific predator types and the level of urgency, and calls not distinctively related to specific predator types. This system is therefore highly suitable to address questions regarding vocal development of alarm calls. Since captive environments often lack many of the natural predators that wild animals experience, research on captive animals can also offer additional insight into how experience with predators may influence a species’ capabilities of responding to them. I collected behavioural observations of naturally occurring predator events, and conducted playback and manipulation experiments at different stages during juvenile development in wild and captive populations. Although young meerkats were able to respond correctly to alarm calls within three months, their probability of doing so increased as they grew older. Young were also likely to gather cues from other group members by looking towards them or running to them. These results suggest that experience is needed to perfect the alarm-call responses of young. However, young showed correct responses to alarm calls signalling predators closeby at an earlier age than to those signalling predators far away, indicating that responses may also be adapted to the level of risk posed by different situations. Correct responses were not, however, contingent upon the particular predator approaching. In terms of call production, young were less likely to utter alarm calls than were adults, but also less likely to look out for predators. Since alarm calls were more likely to be given by vigilant young, the increase in alertness with age might be responsible for an age-related increase in alarm calling. Nevertheless, alarm calls which are not related to specific predator types were produced much earlier than predator type specific calls, indicating that some learning may also be involved. Experience also seems necessary to restrict alarm calling to predators belonging to particular classes. In contrast, although the alarm calls of young underwent slight modification during development, changes which are likely to reflect physical maturation, they were more or less structurally indistinguishable from those of adult calls. All alarm calls that have been documented in the wild also occurred in captivity. The acoustic structure, however, differed slightly from that observed in the wild, but may only reflect differences in arousal. Without experience of odours from predators, captive-born meerkats distinguished between faeces of potential predators and non-predators, similar to that of wild individuals. Together, these findings show that young animals come to classify predators through a mixture of innately recognised features and gradual modification as a result of experience,and provide an important contribution to the small existing literature on predator avoidanceontogeny

Ontogeny of alarm call responses in meerkats, Suricata suricatta: the roles of age, sex and nearby conspecifics

Given the strong selection on prey animals to escape predation, early development of correct avoidance strategies should be favoured. We studied the development of responses to conspecific alarm calls in a free-ranging population of meerkats in South Africa. Through behavioural observations of naturally occurring predator encounters and playback experiments, we monitored responses of young individuals from emergence (3 weeks) to 6 months of age and compared them with those of adults (>12 months). Although the total proportion of responses differing from those of adults was low during the observed period, the probability of responding like adults increased with age. Female young, who remained in closer contact to adults than did male young, were also more likely to show adultlike responses. The largest proportion of non-adultlike responses was shown before reaching independence at 3 months of age, and during this time young commonly ran immediately to a nearby individual when hearing an alarm call. After playbacks of alarm calls, young also reacted more slowly, resumed foraging sooner and spent less time vigilant than did adults.We conclude that young may need experience during early development to associate an alarm call correctly with the type of threat and appropriate response. Older group members may also serve as indirect models, perhaps helping young to form this association

Studying alarm call communication in Meerkats.

Meerkats (Suricata suricatta), as many other animals, suffer from a high mortality rate due to predation. Any behaviour facilitatingthe avoidance of predators is therefore under strong selection. In addition to a coordinated sentinel system, meerkats have developed a sophisticated alarm call system where the acoustic structure of alarm calls provide listeners with information about both the type of predator approaching and the level of urgency. This allows receivers to respond appropriately to calls emitted in a specific context. Using a combination of behavioural observations and field experiments, our research team has investigated questions regarding alarm call communication in groups of free ranging meerkats in South Africa for the past 10 years. Our aim with this paper is to provide an overview of how we approached the study of alarm call communication. The methods applied may also be used to investigate any other vocal communication

Motivation before meaning: motivational information encoded in meerkat alarm calls develops earlier than referential information.

In contrast to historical assumptions about the affective nature of animal vocalizations, it is now clear that many vertebrates are capable of producing specific alarm calls in response to different predators, calls that provide information that goes beyond the motivational state of a caller. However, although these calls function referentially, it does not mean that they are devoid of motivational content. Studies on meerkats (Suricata suricatta) directly support this conclusion. The acoustic structure of their alarm calls simultaneously encodes information that is both motivational (level of urgency) and referential (predator specific). In this study, we investigated whether alarm calls of young meerkats undergo developmental modification and whether the motivational or the referential aspect of calls changes more over time. We found that, based on their acoustic structure, calls of young showed a high correct assignment to low- and high-urgency contexts but, in contrast to adults, low assignment to specific predator types. However, the discrimination among predator types was better in high-urgency than in low-urgency contexts. Our results suggest that acoustic features related to level of urgency are expressed earlier than those related to predator-specific information and may support the idea that referential calls evolve from motivational signals