Romantic love seems to be a nearly universal phenomenon, appearing in every culture for which data are available and in every historical era. This chapter first reviews research on how ordinary people construe love. Then it turns to how researchers have understood and measured love, organizing its discussion around the theme of types of love. Next it covers the course of love with a focus on falling in love. It then reviews several approaches that have been particularly influential in specifically focusing on understanding the dynamics of romantic love, especially with regard to passionate love. It concludes with a brief review of the work on other kinds of love in relationships. The authors hope that this review has conveyed their view that the study of love is both important and a thriving scientific endeavor, offering both a solid foundation and vast opportunities for significant future work.

Couple conflict has received significant attention in couples research, chiefly because poorly managed conflict raises risk for a host of negative outcomes including relationship dissatisfaction, divorce, domestic violence, occupational impairment, and poor child well-being. Effective conflict management is a central target of couple therapy and relationship education. In this chapter, we define couple conflict, describe the frequency and common topics of conflict, and provide examples of how researchers measure conflict. We then describe different ways that couples manage conflict, highlighting effective and ineffective conflict management behaviors and how they affect relationship functioning. Next, we describe conflict and conflict management among historically underrepresented couples. Last, we present information on relationship interventions that target couple conflict and describe future directions for research on couple conflict.

Research has advanced our understanding of the role of self-disclosure in the initiation, development, maintenance, and ending of relationships. In this chapter, we review theoretical and empirical milestones in our understanding of self-disclosure, particularly its role in relationships. We show that research on self-disclosure has shifted from a focus on the individual to a focus on the interpersonal nature of disclosure processes. Self-disclosure occurs between people and triggers a cyclical process that is specific to a particular relationship with a particular partner. Self-disclosure processes fluctuate over time. They shape, and are shaped by, relationships. We propose that self-disclosure serves as a seismograph of relationship quality. It is essential in interdependent relationships and key to unraveling how people perceive the quality of their relationships. Throughout the chapter, we identify unanswered questions that offer promising avenues for future research.

This chapter is devoted to developing and clarifying one of the most unique and important constructs of attachment theory: the internal working models (IWMs) by which relationships influence other relationships and personality. We begin by describing how IWMs develop, discuss different definitions and conceptualizations of IWMs associated with different developmental stages, and then offer a new way of thinking about IWMs as both implicit and explicit representations that function at different levels of awareness. We then discuss factors that promote stability and change in IWMs, highlighting how earlier experiences with attachment figures may shape subsequent IWMs associated with other attachment figures. We next present a framework outlining the conditions under which IWMs associated with specific attachment figures earlier in life can become “activated” to influence how people think, feel, and/or behave with their current attachment figures. We conclude by proposing several promising directions for future research.

This chapter argues that the way that employers responded to the growing problem of stress revealed continuity in terms of the contingent approach to, and explanation of, employee stress as a problem of the individual, rather than an environmental or organisational one. Popular representations of the stressed and the development of ideas about ‘burn-out’ also highlighted continuities with previous attempts to identify and categorise those most susceptible to stress. It argues that the institutionalisation of stress within work and domestic life contributed to a growing conceptualisation of the individual as victim. While this liberated the sufferer from being the cause of their own suffering, it also reduced their agency and still implied a degree of inherent personal weakness, consistent with the conceptualisation of stress throughout the century.

Social networks have always influenced the day-to-day interactions of people, and our chapter highlights the latest research on the significance of these noteworthy social ties in people’s personal relationships. We attend to both romantic relationships and friendship connections, focusing on themes of network effects in relationship formation, maintenance, and dissolution. The findings we review underline the notable ways in which the social environment shapes our closest connections and often strengthens them. We also discuss the extension of network science to investigate marginalized relationships, such as those of sexual minorities, and note the potential for social networks to have a “dark side” in which social connections become problematic. We then address emerging scholarship regarding the positive and negative links between COVID-19 and social networks. Finally, we consider future avenues for research on this notable topic.

Focusing on Home Front experiences in the Second World War, this chapter contrasts early unsubstantiated government concerns about the psychiatric impact of bombing on the population with the experience of civilian stress that arose largely from the daily strain of wartime living and the specific demands made of workers in a wartime economy. It argues that the high levels of absenteeism that so concerned employers and government, constituted one of the few ways that conscripted women workers had for achieving agency in their disrupted and challenging Home Front domestic lives. Discussion of attempts to mitigate wartime strain, through the development of institutions such as Roffey Park Rehabilitation Centre or the work of organisational Welfare Officers, reveals recognition of employee suffering, but also the very contingent nature of these efforts. Against a backdrop of expected collective wartime stoicism, both reveal assumptions about individual, inherent weakness as the cause of stress.

This chapter delves into the neurochemical basis of human engagement with mind-altering substances and experiences. Focusing on the dopamine, serotonin, and endorphin systems, it explains how thrill-seeking and novelty-preference are hardwired into the human brain. Drawing from neuroscience, evolutionary biology, and psychology, it argues that the drive for stimulation and altered states serves adaptive purposes — enhancing creativity, resilience, and social bonding. The chapter also considers how addictive tendencies can arise from evolutionary mismatches, wherein modern environments amplify stimulation beyond biologically tolerable limits. Special attention is given to adolescent risk-taking behaviour and the role of reward pathways in shaping patterns of substance use and behavioural addiction. By connecting ancient impulses to modern neurochemical insights, the chapter sets the stage for understanding both the allure and the danger of substances and technologies that exploit these pathways.

This chapter analyses the historical transformation from ritualistic and therapeutic use of mind-altering substances to their global regulation and criminalisation. Focusing on the colonial and industrial eras, it highlights how opium, coca, and alcohol were recontextualised as economic commodities and instruments of empire. The chapter tracks the emergence of international drug control regimes, moral panics, and racialised legislation — particularly the British Opium Wars, US Harrison Narcotics Act, and global treaties. The intersection of state regulation, corporate profit, and public health is critically examined through case studies including the US opioid crisis. In parallel, sugar and caffeine are discussed as ‘soft’ stimulants that escaped moral scrutiny despite their neurochemical effects. The chapter concludes with a comparative look at regulation and commodification, showing how different substances became entangled in legal, moral, and economic narratives.

Research concerning the variety of close relationships adults maintain, initiate, cease, and lose during middle and later adulthood has been fast growing in recent decades. Much of the theoretical and empirical work in this field has aimed to overcome views of older age as a time of loss and decline, both individually and socially. Moreover, recent trends have focused on the increasingly diverse experiences of the aging population. This includes not only extended life expectancy – and, importantly, extended healthy life expectancy – but also demographic changes, including larger proportions of racial/ethnic minorities attaining older age; new cohorts of openly LGBTQ adults entering mid and later life, many of whom represent the first generation of same-sex married couples; and the phenomenon of “gray divorce” and romantic repartnering in the years beyond age 50. This chapter will cover both the history and foundations of research on close relationships in middle and later life, as well as these recent trends in the field, finishing with an eye toward future directions as both the aging population and our perceptions of it continue to change.

Chapter 10 covers the first of the three background factors of store atmospherics – sound. The direct behavioural response to playing music and sound in stores has been studied for a long time. Early research, for instance, showed that the tempo of the music had an influence on how quickly shoppers walked. More recently, the focus has been on how the shoppers perceive the music, so that if the music makes shoppers happy it will increase both the positive attitude towards the store and the money spent on the shopping trip. There is also research showing that music can have a spreading activation effect. Hence, playing classical music might activate thoughts of more premium products, which make shoppers buy more expensive brands. Some studies have focused on how music might interfere with decision-making, and that popular music might make shoppers sing along with the music and consequently forget to buy what they intended. Along this vein of research, a recent study found that on weekdays, when shoppers’ working memories were depleted, the music served to make the shoppers happier and hence increase their spending. On weekends, however, shoppers were less depleted and happier, and then the music rather interfered with their decision-making, so it had a null or even negative effect on the spending.

People form different types of relationships with others. One common, valued, type is a communal relationship. In communal relationships, people assume responsibility for one another’s welfare and give and seek responsiveness non-contingently. Here we review ways in which communal relational contexts shape people’s emotional lives. In communal relationships, giving and receiving non-contingent responsiveness is linked to positive emotion, whereas failure to do so or behavior indicative of following inappropriate norms (e.g., norms governing transactional relationships) leads to negative emotion. In addition, the presence of communal partners often reduces threat and enhances the intensity of positive and negative reactions to environmental stimuli. Communal contexts are associated with greater expression of emotions signaling one’s own needs (which partners sometimes socially reference as signs of their own needs) and with expressing more indicative of empathy and care for the partner. All these effects can feed back and strengthen communal relationships.

We examine family systems and family relationships. Using family systems theory (Cox & Paley, 1997, 2003; Minuchin, 1985), we focus on how families are viewed as a hierarchically organized system, comprised of smaller relationships (i.e., subsystems) such as parent–child relationships, embedded within larger systems such as extended families and their broader social ties. We organized the discussion of subsystems as follows: (a) Core subsystems, including relationships of romantic partners, coparenting alliance, parent–children, and siblings; and (b) Subsystems with broader social ties, in the form of extended family and/or intergenerational ties, including coparenting alliances in post-divorce or foster families as well as parents and parents-in-law relationships. We also consider these various subsystems within and across diverse families and family contexts, attending to aspects of gender, family structures, income, sexual orientation, race/ethnicity, cultures, and national origins. We end with suggestions for future research (e.g., combining the lenses of family systems with intersectionality).

Chapter 12 covers research on priceperception and price strategy, this chapter focuses on how to communicateprices, especially reduced prices, in the best way. Research projects show a wide variety of ways to communicate when it comes to the efficiency of price promotions. To truly understand how to optimise a promotion, one must, therefore, know how to communicate the discount. Research on price communication shows several psychological effects such as anchoring effects in which a multi-unit promotion leads to increased sales simply because it suggests that shoppers can buy more than one package of the item. The effect also remains without a discount. Another effect is that the numerical value stated on the price sign has more of an effect than the actual meaning of the numbers. For example, a 20% discount on a product that sells for £10 should be stated as −20% and not as −£2 (since 20 is a higher number than 2). However, if the original price is £200, the discount should be stated as −£40 and not as −20% (since 40 is a higher number than 20). Other research shows that different shoppers are sensitive to different promotion techniques, suggesting that retailers have the option of to tailoring promotion techniques to their target group of customers.