In this thesis I present new interferometric ¹²CO observations of 30 early-type galaxies (ETGs). These galaxies were the brightest ~2/3 of CO detected ETGs from the complete, volume limited Atlas^3D survey. By including literature data I construct the largest ever sample of mapped ETGs, containing 41 objects, and use this sample to analyse the morphology, kinematics and origin of the molecular gas. Many of the galaxies in this sample have relaxed molecular discs, but polar structures, rings, bars and disturbed gas distributions are also present. Around half of the galaxies have molecular gas that follows the stellar light profile, similar to molecular gas in spirals, while others have molecular gas excesses, truncations, rings or composite profiles. The molecular gas extent is smaller in absolute terms in ETGs than in late-type galaxies, but the size distributions are similar once scaled by the galaxies optical/stellar characteristic scalelengths. Cluster environments, however, lead to systems having denser, more compact molecular reservoirs. I find that molecular gas is an excellent kinematic tracer, even in high-mass ETGs, and thus molecules may be the kinematic tracer of choice for probing the M/L evolution of galaxies over cosmic-time. I use this knowledge to construct the first ever early-type CO Tully-Fisher relation, and show that it is offset from the Tully-Fisher relation of spirals by 0.98±0.22 magnitudes at Ks-band. I find that a third of my sample galaxies have their molecular and ionised gas kinematically misaligned with respect to the stars, setting a strong lower limit on the importance of externally acquired gas (e.g. from mergers and cold accretion). The origin of the molecular gas seems to depend strongly on environment, with externally acquired material being common in the field but nearly completely absent in Virgo. Furthermore, my results suggest that galaxy mass may be an important independent factor associated with the origin of the gas, with the most massive fast-rotating galaxies in our sample always having kinematically aligned gas.

Family is a unit of socialization and transmitter of social, cultural and economic resources. Thus family arrangements may result in unequal future outcomes for the children growing up in them. A case in point is children from single parent households. The aim of this study is to investigate whether children growing up in single parent households in Sweden experience growing disadvantages during the life course, compared to children from two-parent households, and if socioeconomic factors explain this association. Previous literature shows that children from single parent households are disadvantaged but few have investigated the long term effects of childhood household composition in Sweden and whether disadvantages grow over time.  Using Swedish representative, longitudinal data from Generations and Gender Survey round 2 (GGSII), individuals living in Sweden during childhood between ages 20 to 59 were observed during the years 1990 to 2019. With ordered logistic regression for each year, earnings trajectories could be analyzed, with semi-elasticities used for interpretation.  The results showed that respondents from single parent households fare worse in future earnings compared to respondents from two-parent household. This is explained by differences in educational attainment: children from single parent households have lower educational level which produce lower future earnings. The effect is statistically significant during several years after 2010, however, the results show no evidence of growing disadvantages. Socioeconomic background partially alter the association but not entirely. Whether socioeconomic background functions as a confounder or a mediator to the association has not been determined in this study but is an important task for future research in order to establish the causal nature of socioeconomic background in relation to childhood household composition and children’s future outcomes.