Proposals to reflect on procreation in ways that take into account the interests of people other than the procreators are also discussed by contemporary advocates of population engineering. These authors make two types of claims: Malthusian-inspired claims regarding the size of the population (Cafaro 2012; Das Gupta 2014; Hickey et al. 2016; Rieder 2016; Young 2001) and eugenics-inspired claims regarding the structure of the population (Anomaly 2014, 2018; Brock 2005). The first group focuses on the toll of bringing new persons into the world on resources and the environment. They maintain that there are good moral reasons to favour adoption instead of relying on costly assisted reproductive technologies (Overall 2012; Rulli 2016b), to refrain from having more than one child (Rieder 2016), to pursue alternative ways to ‘make kin’ instead of procreating (Haraway 2015) and to forgo or limit procreative aspirations altogether (Cafaro 2012; Conly 2015; Das Gupta 2014; Rieder 2016; Young 2001). The second group focuses instead on population structure and on the costs of unconstrained procreation for current and future generations. Their view is that the problem with an unconstrained procreative behaviour is not ‘too many people’, but too many of a certain kind of people (Anomaly 2014, 2018; Brock 2005). What unites the claims of authors concerned with the size of the population and authors concerned with its structure, is that they question whether an individual-centred framework is appropriate to address normative challenges raised by procreation. To counter the shortcomings of this framework, they frame their proposals in ways that consider the cumulative effects of individual procreative decisions on third parties. These authors also broadly agree that the interests of existing and future people may constitute a pro tanto reason in favour of interfering with prospective parents’ reproductive freedom (Anomaly 2014, 2018; Brock 2005; Rieder 2016; Rulli 2016b).

For instance, according to Jonathan Anomaly (2014, 2018), bearing and raising children has “far-reaching effects on the genetic composition, cultural trajectory, and general welfare of future people” (Anomaly 2014, p. 172). Due to these far-reaching effects, procreation needs to be organised in ways which are beneficial to both future people themselves and those around them. One way of doing so would be to influence the structure of the population by favouring the transmission of traits such as creativity, humour, productivity, intelligence and compassion, which are beneficial both to those who have these traits and for others. Adopting an impartial moral standpoint leads to the conclusion that it is better to bring into the world people who will have good lives and whose lives can contribute to the well-being of others (Anomaly 2014). This means that, all things being equal, the birth of children who have traits which are both beneficial to them and to the community of people around them should be favoured. Anomaly grants that more people may translate into more producers, more welfare and a larger work force to support an ageing population, but stresses that people are not equally productive and that “some represent a net cost to their society, or to the world” (Anomaly 2014, p. 176).

While Anomaly is concerned with the structure of the population, other authors are concerned with its size. These authors focus on the different strategies which could be devised to mitigate the negative effects of climate change and to reduce anthropogenic greenhouse gas emissions. Travis Rieder (2016) and others (Das Gupta 2014; Hickey et al. 2016; Murtaugh and Schlax 2009) contend that the most effective way to reduce such emissions is to decrease the size of the population by changing people’s procreative behaviours, as procreation plays an important role with respect of the quantity of these emissions (Harte 2007; Murtaugh and Schlax 2009; Nolt 2011). The effects of climate change on people’s well-being call, in their view, for pro tanto moral reasons to refrain from procreation or, at least, for reducing the number of children being born. For instance, Rieder (2016) argues that people have “procreation-limiting duties” (Rieder 2016, p. 9) as:

There are too many people on earth, together emitting too much GHG much too quickly. […] The public health crisis of overpopulation leads to the intuitive conclusion that morality might demand of each of us that we do not contribute to such a crisis. (Rieder 2016, p. 10)

Authors in favour of carrying out population engineering advocate for measures that seek to address normative challenges raised by the far-reaching effects of individual procreative decisions. At the same time, they are cautious as to the potential negative externalities of curtailing people’s freedom. They adopt different strategies to address the tension between the interests (and the freedom) of individual procreators and the interests of other people. Rieder (2016), for instance, argues that there is more to morality than what is within one’s rights. He contends that acting morally entails reducing one’s own family size even if this is at odds with one’s own rights. Anomaly (2014) instead focuses on reasons to exercise caution in “moving from social norms that nudge people to make socially beneficial reproductive choices, to using state institutions that shape reproductive choices” (Anomaly 2014, p. 182). These reasons for caution are: the lack of adequate genetic knowledge; the value of reproductive freedom; and that agents carrying out population engineering may “possess imperfect information” and “face perverse incentives” (Anomaly 2014, p. 182).

The knowledge of how genes influence behavioural traits such as empathy and intelligence (or even aesthetic traits such as eye colour or height) and the capacity to edit genes to favour the expression of these traits are in their infancy to say the least. Despite this, I would argue that the current lack of knowledge may not represent per se an insurmountable challenge to carrying out population engineering programmes. It may also not represent, as it were, an insurmountable (ethical) argument against these programmes. Studies on the hereditability of IQ date back to the beginning of the twentieth century and some progress has been made (for a review, see for instance: Ritchie 2015). Moreover, if it becomes clear that population engineering and Anomaly’s aims of improving the structure of the population can be achieved not through prenatal/pre-conception genetic interventions, but thanks to controlled epigenetic influence, education, welfare provisions and other post-natal measures, then the question of the desirability of population engineering programmes will remain. In other words, the first reason for caution identified by Anomaly (2014) is a contingent matter. Similarly, with respect to the second reason for caution, it is important to consider that even liberal defences of reproductive freedom allow some degree of interference from third parties. What matters is hence establishing whether the harms engendered by what reproductive freedom protects warrant some kind of restriction on people’s procreative decisions. This needs to be discussed while bearing in mind a third reason for caution identified by Anomaly (2014), namely the risk that third parties may “possess imperfect information” and “face perverse incentives” (Anomaly 2014, p. 182). It is to this third reason that I now turn.

What could go wrong

As I have argued above, an important lesson of past proposals to rethink procreation is that epistemically and politically troubling beliefs can give rise to ethically troubling strategies for intervening in procreation. The problem of these past proposals is not the adoption of a broader framework to reflect on and organise procreation. Rather, their troubling component rests on how trade-offs between competing interests were made and burdens and benefits were distributed. In this section, I argue that this lesson is also relevant for contemporary defences of population engineering programmes.

I identify two main shortcomings of present population engineering programmes and proposals: acquiring reliable data on who should come into existence and assessing this data. Regarding proposals aimed at tackling the structure of the population, the first shortcoming concerns the feasibility of acquiring data on the type of people who could be reliably said to contribute to overall increases in the well-being of future people. Anomaly (2014) argues that the best suited to become parents are those with “favorable genetic endowment” and “the means to provide a rich social environment for their children” (Anomaly 2014, p. 174), as both characteristics seem to predict the birth of people whose lives have value both for themselves and for others. However, what counts as favourable genetic endowment and as a rich social environment is a complex notion: whether a given genetic endowment really turns out to be favourable often depends also on people’s social environments. In this sense, the assessment of what counts as favourable genetic endowment cannot be separated from the assessment of what counts as a rich social environment. Not only are these conditions often context-dependent, they are also normatively loaded as what counts as ‘favourable’ and ‘rich’ presupposes the adoption of a certain normative framework as a reference. In other words, in an assessment of whether something is rich or favourable, an impartial moral standpoint will not do. Different groups of people are likely to come up with different assessments of what counts as valuable and competing interests are likely to play a role in these assessments.

This brings me to the second shortcoming. If I am right about the first, there will be competing assessments of what counts as valuable, and therefore different answers to the question of what type of people should be allowed to come into existence. Hence, a reliable mechanism to acquire empirical data that can assist in the selection of the best answers to ground future policies becomes necessary. Acquiring this data seems again normatively loaded and complex: this data could reflect our current ‘status quo biases’ (Bostrom and Ord 2006), racist and discriminatory attitudes (Roberts 1997, 2015) and short-sighted or partial conceptions of valuable lives (Garland-Thomson 2012; Mackenzie and Scully 2007). There are existing studies that document IQ hereditability and a correlation between high IQ and low fertility (Meisenberg 2009). Despite this, delving into the history of research on the mechanisms of human heredity allows to appreciate that a complicated interplay between epistemic and political forces exists: between the quest for knowledge and interventions acting upon that knowledge (Meloni 2016; Roberts 2015). The type of questions asked, the hypotheses formulated, the data collected, and the inferences drawn are all likely to be influenced by existing political views and beliefs (Kitcher 2001). In addition, it is unclear who should decide what data is to be taken into consideration for institutional design and whose normative framework should be used as a reference. The problem, then, is not (or not only) about ‘imperfect information’ and ‘perverse incentives’ possessed by the state, but rather about the difficulty of having reliable mechanisms to assess this information both in the context of state interventions and of shaping social norms.

Regarding the size of the population, it may seem that the proposals outlined above might be less problematic and that the challenges discussed might not apply. Economic growth, increased levels of welfare, empowering women, better educational provision and institutions are all viable strategies to reduce fertility rates. Despite this, the one-size-fits-all model to reduce the size of the population seems to be ill-conceived if the aim is to reduce, for example, climate change hazards (as noted for instance by Haraway 2015; Rieder 2016). Not all people contribute equally to the worsening of climate change and not all people are in an equal position to produce new resources to minimise these negative effects. Hence, it seems reasonable to assume that it would be self-defeating to implement measures which seek to reduce everyone’s birth rates. Population engineering programmes aimed at reducing the size of the population cannot be easily disentangled from population engineering programmes aimed at influencing the structure of the population. The two (i.e. size and structure) cannot be completely separated today, and they were not completely separated in the pastFootnote 9 (Bashford 2014; Connelly 2008; Klausen and Bashford 2010). Contemporary attempts to reduce the size of the population are likely to incur the very same shortcomings identified above, as competing interests are likely to influence people’s assessments of what counts as valuable (i.e. who should procreate and how much) and the decision of who gets to decide in these matters influences which interests will be given priority.