Introduction
Physical activity is a health relevant factor, particularly in affluent societies, where sedentary lifestyles, overweight and obesity are increasingly prevalent among adults (Church et al.
2011; Flegal et al.
2002; Hallal et al.
2012; Ng et al.
2014) as well as children and youths (Fox
2004; Hallal et al.
2012; Ng et al.
2014; Wang and Lobstein
2006). Studies from Germany (Buksch et al.
2014; Lampert et al.
2007; Manz et al.
2014) as well as many other European countries (Riddoch et al.
2004; Verloigne et al.
2012) indicate that children’s average physical activity levels are rather low and often do not meet the minimum level of 60 min of moderate to vigorous physical activity (MVPA) per day, as recommended by the World Health Organization (WHO
2010). Therefore, the promotion of sport and exercise in all stages of the life-course has become a major pillar of health policies (Kahn et al.
2002; Heath et al.
2012; Sallis Bauman and Pratt
1998). Prior research has shown that high and continuous levels of physical activity in childhood and youth are likely to lead to physically active lifestyles in adulthood (Telama et al.
2005). It seems likely though, that sedentary lifestyles are also habitualized in childhood which can negatively affect cardiovascular risk factors in later life stages (Healy et al.
2011; Katzmarzyk et al.
2009; Qi et al.
2015). Hence, further understanding of the development of physical activity and inactivity patterns in childhood are of crucial importance (Hamilton et al.
2015).
Most previous studies have assessed activity levels of children either with activity diaries (Raudsepp
2006; Schoeppe and Trost
2015; Trost et al.
2003; Woll et al.
2011) or accelerometers (e.g., Aznar et al.
2011; Bringolf-Isler et al.
2009; Griffiths et al.
2013,
2016; Riddoch et al.
2004; Steele et al.
2010; Trost et al.
2002). The latter studies have often been concerned merely with a precise description of activity levels. Besides the finding that many children do not meet the activity guidelines, it was shown that the proportion of children below the recommended levels of MVPA is particularly large among girls (Aznar et al.
2011; Crespo et al.
2013; Griffiths et al.
2013; Kettner et al.
2013) and children from lower social status groups (Vorwerg et al.
2013). Moreover, MVPA levels drop with age (Trost et al.
2002; Riddoch et al.
2004). Studies based on activity diaries and questionnaires also have concurrently shown that children and youths from upper and middle class are more likely to be involved in sport and exercise (Jekauc et al.
2013; Mess and Woll
2012; Raudsepp
2006; Schoeppe and Trost
2015). Children’s sports and exercise participation is closely associated with their family’s socio-economic status (SES) and their parents’ lifestyle and support (Burrmann
2005; Edwardson and Gorely
2010; Loprinzi and Trost
2010; Nagel and Ehnold
2007; Wijtzes et al.
2014). Parents’ SES is not only correlated with children’s sports activities in leisure time and their membership in sports clubs, but also with participation in toddler gymnastics (Schmiade and Mutz
2012), motor abilities (Klein et al.
2011), swimming skills (Kuntz et al.
2016), the use of public swimming pools (Audrey et al.
2012) and outdoor play activity (Wijtzes et al.
2014).
However, the mechanisms and transmission paths that lead from parents’ SES to children’s physical activities are not nearly as well understood. Socialization theories generally state that behavior patterns and personality traits are developed in a life-long process and in interaction with the social and material environment. For example, Hurrelmann (
2009) has described individuals as “productive processors of reality” and thus claimed that personality is not solely coined by environmental factors. Instead, subjects have agency to actively shape and co-construct their own development. However, when it comes to children it is also undoubted that the family is the primary entity for socialization and provides important stimuli that profoundly influence attitudes, values, cognition and behavior and thus partially predetermine children’s further development (Duncan et al.
2005). Hence, through family interactions attitudes and behavior patterns can be transmitted from the parent generation to their offspring.
This inner-familial socialization and transmission process can be applied to sport and exercise as well. Prior research suggests that several key mechanisms may be at work which all are compatible to the general socialization framework. It is typically claimed (a) that parents work as
role models for their children, set an example and thus convey their own class-based sports orientations and practices to their children (Edwardson and Gorely
2010; Pugliese and Tinsley
2007). Hence, parents own sports activities are considered a crucial factor in the sports-related socialization process of their children. (b) Moreover, parents can provide social
support for sports activities of their children actively, for instance, they could play sport together with their children, encourage them to start sports activities or accompany them to competitions (Burrmann
2005; Loprinzi and Trost
2010; Schoeppe and Trost
2015). (c) Besides active support from parents, sports activities are also fostered through
sports facilities in the home environment. In families where children have access to a large variety of sports equipment, like skateboards, balls, bicycles, skiing equipment, gym and outdoor fitness equipment, it seems more likely that children are inspired to play sport in their leisure time (De Lepeleere De Bourdeaudhuij et al.
2015). (d) Finally, parent’s
attitudes and orientations towards sports are considered of importance, for instance, the value they see in sports activities in childhood (Kahn et al.
2008; Hamilton et al.
2015). Some parents may believe sport to be extremely important in regard to personality development, social skills acquisition and character building, while others may be more skeptical in regard to these outcomes. In families where sport is given more value with regard to developmental outcomes, children may receive more stimulation and may be inclined to exercise by themselves (Wheeler
2011).
Children from higher social classes may be privileged with regard to all of these conditions of sports-related socialization. In general, their parents are more likely to be actively involved in sport by themselves (Breuer and Wicker
2008; Studer et al.
2011) and may associate sport with better developmental outcomes (Cachay and Thiel
1998). Moreover, they may be more likely to support their children’s sports activities, be it through active support or through investments into equipment (Burrmann
2005; Loprinzi and Trost
2010; Schmiade and Mutz
2012). Hence, the transmission of class-based inequalities from parents to children is likely to operate on these four mechanisms.
This paper aims to better understand the inner-familial transmission process through which social inequalities translate into differences in MVPA levels in children. We analyze this process in the age group of 6- to 11-year old children, an age in which the course is likely to be set for later life-stages due to a habitualization of sport and exercise patterns. In this study physical activity measures derived from the children and questionnaire data collected from the parents are combined. Physical activities are recorded with accelerometers, a technology which allows to assess objectively the duration and intensity of physical activities performed by the children. This measure thus includes MVPA beyond the narrow scope of organized sports and physical education, for instance, walking, playing at playgrounds or romping around. Individual differences in daily levels of physical activity are then explained by a multitude of possible socialization factors, collected with parent questionnaires. This allows to identify the most important ‘transmission belts’ that lead from parents’ attitudes, values and behaviors to their offspring’s daily physical activity routines. Based on the results of previous research it is hypothesized that MVPA in children increases with (1) a higher educational level of the parents; (2) a higher income level of the family; (3) the support the child receives from parents for sports activities; (4) the sports activities the parents pursue for themselves; (5) the parents’ belief in sport-for-good, i.e. in sports’ capacity to positively impact personality and development; (6) the sports equipment available in the family’s home.
Discussion
This study aimed at providing further insights into the transmission paths that lead from parents’ socio-economic status (SES) to children’s moderate-to-vigorous physical activity (MVPA). Whereas prior studies often focussed on organized settings for sport and exercise, this study was able to capture daily physical activity patterns, which include activities beyond the narrow scope of organised sports in clubs or schools. The findings demonstrated that daily patterns of MVPA in 6- to 11-year old children are subject to social inequalities and that parents’ SES—measured with educational and income levels—matters in this regard. However, more closely related to the child’s MVPA are the parents own sports activities, their support for the child’s physical activity—including their willingness to play sport together with their child—and their beliefs in sports’ capacity to foster personality development, social integration and character building. These aspects of sports-related socialization seem to play the key roles in the familial transmission process, indicating that attitudes, support and behavioural modelling represent distinct aspects of the familial sports-related socialization process. Although only marginally significant, the sports equipment at home also predicts MVPA in children. Hence, simply having a variety of sports equipment at home—e.g. balls, rackets, skates, boards—seems to motivate children to engage in more active leisure pursuits. A similar effect has been shown by De Lepeleere et al. (
2015).
Gender was revealed as a strong predictor of MVPA in all model specifications, with girls being less active than boys. This effect is well-known (Verloigne et al.
2012). However, the present research demonstrates that the gender effect on MVPA is independent of parental SES and parental support. Moreover, neither age nor weight status were relevant predictors of MVPA. Regarding the effect of weight status, previous research has shown inconsistent results with some studies demonstrating that MVPA is inversely associated with overweight (Kahn et al.
2008), inversely associated with overweight in boys but not girls (Basterfield et al.
2014) or even positively associated with overweight (Kettner et al.
2013). Hence it seems that the association between weight status and MVPA in children is more complex than widely assumed and that overweight children are not per se physically inactive. Somewhat surprisingly, religious affiliation was revealed as a significant predictor of MVPA in children. Previous research has shown that religiousness is associated with participation in club-organized sports activities (Burrmann et al.
2015) and with spending less time with home-based entertainment activities, e.g. video games (López-Sintas et al.
2017). If such leisure patterns are associated with religion, they may produce higher levels of MVPA in religious children.
Generally, the results confirm findings of previous studies from Germany (Burrmann
2005; Nagel and Ehnold
2007; Schmiade and Mutz
2012) as well as from other countries (De Lepeleere et al.
2015; Hayoz et al.
2016; Raudsepp
2006; Schoeppe and Trost
2015), which have also addressed the intergenerational transmission of sport-related lifestyles in the family. These studies, however, have assessed sports activities by questionnaire and thus only in a narrower sense without including activity routines outside of sport. In line with the results of the present research, these studies demonstrated that parents’ sports activities and social support as well as their attitudes towards sport mediate the association between SES and children’s and adolescents’ organized sports activities. The present study has shown that these associations also hold true for daily physical activity routines, which include manifold activities outside the scope of organised sport, like playing at playgrounds, romping around, walking or cycling to school etc. Hence, social inequality is not only important for participation in club-organised sports, but also for general physical activity levels.
A very high share of children in Germany exercises in sports clubs. Membership figures reach its climax in the age group of 7- to 10-year olds, when roughly 70% of all children are sport club members (Manz et al.
2014). However, despite these high levels of participation in club-organized sporting activities, only a minority of the children meet the WHO physical activity recommendations, so that interventions in communities and schools are called for (Sutherland et al.
2016). Findings presented here suggest that interventions for physical activity promotion should aim at low status groups and possibly schools in underprivileged areas. Studies have shown that interventions to promote MVPA in schools can be effective in decoupling physical activity from SES (Vander Ploeg et al.
2014). Moreover, change processes in families could be initiated by increasing parents’ awareness for the health and developmental benefits of sport (Sanders and Burke
2014). However, future research is needed to provide evidence which of these measures are effective in fostering MVPA in children and disassociating MVPA levels from parents’ SES.
A strength of the present study is that MVPA levels have been measured objectively with accelerometers. This is particularly relevant in childhood as the main proportion of children’s physical activity takes place during unstructured play, (Bringolf-Isler et al.
2009) which is characterized through very short activity bouts (Ruch et al.
2013). These activities cannot be remembered reliably, especially not by children, and thus cannot be captured appropriately with diaries or questionnaires. A second problem of questionnaire-based data is that children and adolescents differ in their subjective understanding of physical activity. Some may subsume light activities like walking, cycling, or climbing stairs to MVPA while others only count vigorous sports activities. In view of these problems, objective measures can claim a higher validity compared to self-reported data (Beneke and Leithäuser
2008).
As a matter of course, this research is not free from limitations. First, the study has a cross-sectional design, so that children’s MVPA and familial practices were measured at the same time. Hence, no inferences on causality can be drawn from the data. Although there are good reasons to assume that parents influence MVPA in their children through their behaviour, support, and attitudes, it cannot be ruled out that a high level of MVPA in a child can also change parents’ stance towards sport and exercise. Second, this study was concerned with socialization processes in the family, and other social contexts of socialization (peers, schools etc.) were largely ignored. Finally, it has to be kept in mind that this study took place in a regional context and thus results may not be generalizable to the population of elementary school children in Germany. Although the sample represents various social and ethnic groups it has to be kept in mind that Göttingen is a University town with a high proportion of academics, so that findings may be biased due to idiosyncrasies of this particular region.