In the ecocultural framework (Figure 1.1), two major sources of influence on the development and display of behavior were postulated: ecological and sociopolitical. The latter involves contact with other cultures and sets in motion the process of acculturation. This chapter examines some core aspects of this process and some of its outcomes. Related to acculturation psychology is a field that has come to be known as intercultural psychology. These two branches of psychology are sometimes examined together because they both involve intercultural contact. However, they are clearly distinguishable: in acculturation, the focus is on how individuals change in order to live side by side with persons of different cultural backgrounds; and in intercultural work the focus is on how the two parties relate to each other. We are devoting separate chapters to these issues. In Chapter 14, intercultural relations are examined, and a further chapter (Chapter 15) is devoted to an important aspect of both acculturation and intercultural psychologies: intercultural communication.

In this chapter, we will first discuss the concept of acculturation and the different kinds of people undergoing acculturation. We also present a framework for understanding and studying acculturation.

This chapter focusses on health in relation to cultural context. It begins with an introduction to some conceptual issues including some definitions of central terms, how health problems can be compared, and a brief overview over how culture and health may be related. The chapter also examines possible links between culture and mental illness (psychopathologies), and how different societies attempt to relieve mental health suffering and problems (psychotherapies). The chapter also focusses on positive mental health, health behavior from the point of view of the United Nations Millennium Development Goals and how ecology and population may be related to health.

Health has been defined by the World Health Organization (WHO) as “a state of complete physical, mental and social well-being, and not just the absence of disease or infirmity” (WHO, 1948). However, studies have shown that the very concept of health differs across cultures (Helman, 2008). From a western point of view, health is often conceptualized in a biomedical model, where health is seen in terms of disease. Disease in turn is seen as originating from a specific and identifiable cause within, or arriving from outside, the body. Views from other cultures regard health as an imbalance either between negative (yin) and positive (yang) forces as in the case of Chinese medicine, or elemental ingredients (bhutas) and waste products from food (vayu, pitta and kaph) in Indian Ayurvedic medicine.

This chapter seeks to portray comparative research and applications in the field of intercultural relations. It begins with an examination of the concept of intercultural strategies, which is parallel to that of acculturation strategies introduced in Chapter 13. One of these strategies (multiculturalism) is both contested theoretically and examined empirically; some of these ideas and findings are then presented. The chapter continues with a presentation of some core theories and concepts, and illustrates them with selected research and applications across cultures.

The study of intercultural relations can be viewed as a core part of cross-cultural psychology. It shares with the subfield of acculturation a focus on psychological phenomena that result from contact among cultural groups and their individual members. And like acculturation, intercultural relations research examines the ways in which people work out their lives while living together in culturally plural societies (Brewer, 2007; Sam and Berry, 2006; Ward, 2008). The various kinds of groups that share social space in plural societies have been described in Chapter 13 (including immigrants, refugees, ethnocultural groups, sojouners and indigenous peoples). However, somewhat different from acculturation, intercultural relations phenomena can take place without firsthand contact; they can be rooted in awareness from prior historical contact or from contemporary telecommunications.

The field of cross-cultural psychology can be briefly described as the study of the relationships between cultural context and human behavior. The latter includes both overt behavior (observable actions and responses) and covert behavior (thoughts, beliefs, meanings). As we shall discuss later in more detail, there are rather different interpretations even of this broad description, associated with different schools of scientific research. Most researchers studying behavior across cultures argue that differences in overt and covert behavior should be seen as culturally shaped reflections of common psychological functions and processes. In other words, they are postulating a “psychic unity” of the human species (e.g., Jahoda, 1992). This is the position adopted by the authors of this text. Other researchers, often belonging to a school referred to as cultural psychology, emphasize that psychological functioning is essentially different across cultural regions of the world. For example, Kitayama, Duffy and Uchida (2007, p. 139) argue that different “modes of being” are found in various cultures. Sometimes the two approaches are even presented as two distinct fields of science.

In this book we use the label “cross-cultural psychology” as the overarching name for the field. More specific terms, such as cultural psychology, culture-comparative psychology and indigenous psychology will be used when it is necessary to distinguish orientations within this broader field. The common designation is justified by the shared assumption that culture is an important contributor to the development and display of human behavior.

Throughout this book references have been made to results derived from the theory of complex variables. This theory thus becomes an integral part of the mathematics appropriate to physical applications. Indeed, so numerous and widespread are these applications that the whole of the next chapter is devoted to a systematic presentation of some of the more important ones and a summary of some of the others. This current chapter develops the general theory on which these applications are based. The difficulty with it, from the point of view of a book such as the present one, is that the underlying basis has a distinctly pure mathematics flavor.

Thus, to adopt a comprehensive rigorous approach would involve a large amount of groundwork in analysis, for example formulating precise definitions of continuity and differentiability, developing the theory of sets and making a detailed study of boundedness. Instead, we will be selective and pursue only those parts of the formal theory that are needed to establish the results used in the next chapter and elsewhere in this book.

In this spirit, the proofs that have been adopted for some of the standard results of complex variable theory have been chosen with an eye to simplicity rather than sophistication. This means that in some cases the imposed conditions are more stringent than would be strictly necessary if more sophisticated proofs were used; where this happens the less restrictive results are usually stated as well.

With an initial knowledge of the goals, concepts and methods of cross-cultural psychology that were presented in the introductory chapter, this first part of the book seeks to display research findings on the range of psychological domains that have been examined across cultures. The background materials of Chapter 1 should provide the reader with some basis for understanding and critically appraising the research being described in Part I. The order of the chapters has been arranged to begin with a portrayal of human development in infancy and childhood, then continuing into adulthood and older age. The six chapters that follow present some of the core findings from some decades of research into social behavior, personality, cognition, emotion, language and perception. This sequence of topics attempts to illustrate the varying degree of cultural influences on the display of human behavior. In keeping with the perspective of moderate universalism mentioned in Chapter 1, there is a search for cultural variation in development and display of behavior, as well as for possible commonalities in the underlying psychological processes.

This chapter deals with what has become the most popular research domain in cross-cultural psychology, namely that of social behavior. We start the chapter by discussing various ideas about the relationships between social context and social behavior that have been put forward in cross-cultural psychology and adjacent fields. This is to give you a taste of the breadth of the field and to put the next section in perspective. We then move to the topic of values, which is arguably the dominant topic in contemporary cross-cultural studies of social behavior. After this, we discuss studies on cultural differences in social cognition and behavior as well as their implications for universality or relativism of social psychological phenomena. The last section deals with different notions of culture as a social psychological construct. We end the chapter with a general discussion. In addition, on the Internet you can find a section on the important, but somewhat understudied area of cultural variation in gender differences in social behavior (Additional Topics, Chapter 4).

If you take at random a recent publication of a cross-cultural study, it is most likely to be about social perception, cognition or behavior. This has not always been the case. In the early days of cross-cultural psychology, studies in perception and cognition were much more frequent.

This chapter begins Part II of the book, in which we explore quantum computation in detail. The chapter develops the fundamental principles of quantum computation, and establishes the basic building blocks for quantum circuits, a universal language for describing sophisticated quantum computations. The two fundamental quantum algorithms known to date are constructed from these circuits in the following two chapters. Chapter 5 presents the quantum Fourier transform and its applications to phase estimation, order-finding and factoring. Chapter 6 describes the quantum search algorithm, and its applications to database search, counting and speedup of solutions to NP-complete problems. Chapter 7 concludes Part II with a discussion of how quantum computation may one day be experimentally realized. Two other topics of great interest for quantum computation, quantum noise and quantum error-correction, are deferred until Part III of the book, in view of their wide interest also outside quantum computation.

This chapter explains how to do quantum information processing reliably in the presence of noise. The chapter covers three broad topics: the basic theory of quantum error-correcting codes, fault-tolerant quantum computation, and the threshold theorem. We begin by developing the basic theory of quantum error-correcting codes, which protect quantum information against noise. These codes work by encoding quantum states in a special way that make them resilient against the effects of noise, and then decoding when it is wished to recover the original state. Section 10.1 explains the basic ideas of classical error-correction, and some of the conceptual challenges that must be overcome to make quantum error-correction possible. Section 10.2 explains a simple example of a quantum error-correcting code, which we then generalize into a theory of quantum error-correcting codes in Section 10.3. Section 10.4 explains some ideas from the classical theory of linear codes, and how they give rise to an interesting class of quantum codes known as Calderbank–Shor–Steane (CSS) codes. Section 10.5 concludes our introductory survey of quantum error-correcting codes with a discussion of stabilizer codes, a richly structured class of codes with a close connection to classical error-correcting codes.

Algorithms are the key concept of computer science. An algorithm is a precise recipe for performing some task, such as the elementary algorithm for adding two numbers which we all learn as children. This chapter outlines the modern theory of algorithms developed by computer science. Our fundamental model for algorithms will be the Turing machine. This is an idealized computer, rather like a modern personal computer, but with a simpler set of basic instructions, and an idealized unbounded memory. The apparent simplicity of Turing machines is misleading; they are very powerful devices. We will see that they can be used to execute any algorithm whatsoever, even one running on an apparently much more powerful computer.

The fundamental question we are trying to address in the study of algorithms is: what resources are required to perform a given computational task? This question splits up naturally into two parts. First, we'd like to understand what computational tasks are possible, preferably by giving explicit algorithms for solving specific problems.

Quantum mechanics is the most accurate and complete description of the world known. It is also the basis for an understanding of quantum computation and quantum information. This chapter provides all the necessary background knowledge of quantum mechanics needed for a thorough grasp of quantum computation and quantum information. No prior knowledge of quantum mechanics is assumed.

Quantum mechanics is easy to learn, despite its reputation as a difficult subject. The reputation comes from the difficulty of some applications, like understanding the structure of complicated molecules, which aren't fundamental to a grasp of the subject; we won't be discussing such applications. The only prerequisite for understanding is some familiarity with elementary linear algebra. Provided you have this background you can begin working out simple problems in a few hours, even with no prior knowledge of the subject.

Readers already familiar with quantum mechanics can quickly skim through this chapter, to become familiar with our (mostly standard) notational conventions, and to assure themselves of familiarity with all the material. Readers with little or no prior knowledge should work through the chapter in detail, pausing to attempt the exercises. If you have difficulty with an exercise, move on, and return later to make another attempt.