[From the transformation of age groups to the evolution of social relationships].

"In Western societies, change in family behaviour patterns, increased life expectancy, transformations in the socioeconomic environment and in culture have effected important modifications in the 'age pyramid', the significance of which has fed the debate between experts who have recorded them and who have anticipated their foreseeable consequences. These consequences are examined here in the light of some of their effects on social ties, inside the family and on the community level: the recomposition of the deviations between generations, the appearance of a pre-adult stage, the growth of concomitant responsibilities in relation to ascendants and descendants within family networks, potential concurrent intergenerational conflicts, and the aging of the social fabric [at] the community level. These phenomena in full evolution are a particular incentive to reinforcing the dialogue between demography and sociology." (SUMMARY IN ENG AND SPA)