Evolution of family systems and resultant socio-economic structures

Abstract

Families form the basis of society, and anthropologists have observed and characterised a wide range of family systems. This study developed a multi-level evolutionary model of pre-industrial agricultural societies to simulate the evolution of family systems and determine how each of them adapts to environmental conditions and forms a characteristic socio-economic structure. In the model, competing societies evolve, which themselves comprise multiple evolving families that grow through family labour. Each family has two strategy parameters: the time children leave the parental home and the distribution of inheritance among siblings. The evolution of these parameters demonstrates that four basic family systems emerge; families can become either nuclear or extended, and have either an equal or strongly biased inheritance distribution. Nuclear families in which children leave the parental home upon marriage emerge where land resources are sufficient, whereas extended families in which children staying at the parental home emerge where land resources are limited. Equal inheritance emerges where the amount of wealth required for a family to survive is large, whereas strongly biased inheritance emerges where the required wealth is small. Furthermore, the frequency of polygyny is low in the present model of agricultural societies, whereas it increases for the model of labour-extensive subsistence patterns other than agricultural societies. Analyses on the wealth distribution of families demonstrate a higher level of poverty among people in extended families, and that the accumulation of wealth is accelerated in families with strongly biased inheritance. By comparing wealth distributions in the model with historical data, family systems are associated with characteristic economic structures and then, modern social ideologies. Empirical data analyses using the cross-cultural ethnographic database verify the theoretical relationship between the environmental conditions, family systems, and socio-economic structures discussed in the model. The theoretical studies made possible by this simple constructive model, as presented here, will integrate the understandings of family systems in evolutionary anthropology, demography, and socioeconomic histories.

Culture, ethnicity, and socio‐economic status as determinants of the management of patients with advanced heart failure who need palliative care: A clinical consensus statement from the Heart Failure Association (HFA) of the ESC, the ESC Patient Forum, and the European Association of Palliative Care

“…Families are the basic components of all societies, founded on parental duty, mutually supportive relationships, emotional commitment, and oriented to protection and social bonding. 119 In recent decades, the structure and organization of the family has been transformed, 120,121 with the concept of chosen family 122 adopting a family-centred model of care and healthcare provision. 123 The care provided by family members or friends is an important factor throughout the HF trajectory, but particularly so, in the advanced stages of the illness (online supplementary ).…”

“…Families are the basic components of all societies, founded on parental duty, mutually supportive relationships, emotional commitment, and oriented to protection and social bonding 119 . In recent decades, the structure and organization of the family has been transformed, 120,121 with the concept of chosen family 122 adopting a family‐centred model of care and healthcare provision 123 .…”

Strategi Penghidupan, Manajemen Keuangan, Kerentanan Ekonomi, dan Ketahanan Keluarga Nelayan

“…Menurut Wagner et al, (1985), jumlah anak yang lebih sedikit menjadikan keluarga sedikit mengalami risiko permasalahan kesehatan. Itao & Kaneko (2021) menyatakan bahwa keluarga kecil memiliki tingkat kemiskinan yang lebih rendah dibandingkan keluarga besar. Hasil penelitian menunjukkan lama menikah pasangan sebagian besar > 10 tahun.…”

Emergence of kinship structures and descent systems: multi-level evolutionary simulation and empirical data analysis

“…This can be interpreted as an invasion, imitation or the coarse-grained description of a growing system. This framework, known as the multi-level selection, has been widely adopted in biological and social evolution studies to explain group-level structures [ 27 – 30 , 37 – 39 ]. Previously, we considered a model with three layers, including the intermediate layer of ‘lineage’ between family and society.…”