Our Gemara on Amud Aleph and Beis discusses various halakhic ramifications of mother in law to daughter in law hatred.  What does psycholgy and contemporary social research say about trends and comments of mothers in law?

Researchers Christine E. Rittenou and Jody Koenig Kellas surveyed prior research and itemized and described various forms of hurtful content within Mother-in-Law (MIL) communication:

(Rittenour, Christine E. and Koenig Kellas, Jody, "Making Sense of Hurtful Mother-in-law Messages: Applying Attribution Theory to the In-Law Triad" (2015). Papers in Communication Studies. 68.

http://digitalcommons.unl.edu/commstudiespapers/68 ):

“Vangelisti (1994) argues, the hurtfulness often results from the perception of devaluation. Hurtful messages encompass a wide array of behaviors—verbal and nonverbal—that communicate to recipients a sense of rejection, exclusion, or negative evaluation (e.g., Feeney, 2004; Mills, Naser, & Farrell, 2005) and therefore may induce a complex amalgam of emotions such as fear, anger, humiliation, guilt, and shame. Although often brief, hurtful messages can have a pervasive and potentially lasting impact on the ways parents, children, romantic partners, and friends feel about each other, their relationships, and themselves (e.g., Vangelisti & Young, 2000). The MIL/DIL relationship is rife with reports of negativity, rejection or disassociation, and negative evaluation.”

“The most common problems are MIL’s excessive involvement, control, or general mistreatment toward the son (Merrill, 2007; Rittenour & Soliz, 2009). Similarly, some DILs complain about MILs who criticize or override DILs’ parenting choices, while others complain of MILs’ direct mistreatment or uninvolvement as grandmothers (Merrill, 2007; Rittenour & Soliz, 2009). Grandchild mistreatment often coincides with another noted concern—preferential treatment toward another child or child-in-law and his/her family (Merrill, 2007). Overall, the themes of MIL misbehaviors reflect a sense of over or underinvolvement with the DIL’s immediate family (i.e., spouse and child) and/or criticisms of the DIL and her family of origin, reflecting the undesirable stereotypes cross-culturally ascribed to MILs (Adler, Denmark, & Ahmed, 1989).”

Using what is known as Attribution Theory, Rittenour and Koenig focused their study on the dynamics of how messages from the mother in law are interpreted and under what contexts and circumstances.  Attribution Theory has significant applications to all marital interactions, not just in-laws. 

They assert, “The degree to which a message hurts us also depends on the causes, or attributions, that we assign to the message.”  A key element in attributions depends on whether they tend to be internal or external.  Internal Attributions are when the distressing or damaging event is blamed on a personal deficiency, moral failing and often a continuous pattern. External Attributions are when the distressing event is blamed on some outside factor, and less about a continuous pattern of personal failure.  Not surprisingly, when couples have a frequency of perceived Internal Attributions in their communications, there is more marital discord and distress. 

“Those who attribute another’s negative (i.e., hurtful) behavior as external generally report higher levels of relational satisfaction (a relationship-enhancing bias) than those who attribute them as internal (a distress-maintaining bias; see Manusov & Spitzberg, 2008). The process through which internal attributions exert their harm on relationships is perhaps best shown in comparisons of distressed and non-distressed couples (Baucom et al., 1996). Distressed couples tend to follow a trajectory whereby one spouse hurts the other by violating an expectation. Next, the hurt spouse makes internal attributions and experiences a high level of negative affect. When this spouse responds with his/her own negative communication, the cycle can repeat (Baucom et al., 1996; Manusov, 1990). Whereas non-distressed couples tend to prescribe external attributions to their partners’ negative behaviors, distressed couples tend to have negative relational beliefs that can breed a trajectory of negative communication between partners. This combination of negative communication and negative beliefs about the relationship perpetuates an atmosphere in which negative violations are not easily overlooked, and resentment builds (Baucom et al., 1996). Thus, spouses’ negative behaviors are often attributed to internal causes, thereby helping to maintain the distress in the relationship.”

Another fascinating assertion they make is that you might argue that marital satisfaction colors the attribution,  In other words, if the marriage is good then people tend to have more healthy attributions.  However, in this case, the research shows the egg comes before the chicken:

“We might presume that satisfaction drives attribution type, but longitudinal evidence suggests that the direction of this relationship is reversed. Specifically, in research by Fincham and Bradbury (1987), satisfaction at the initial data collection did not significantly predict couples’ attributions up to one year later; however, particularly for women, initial attributions were linked to later satisfaction scores.”

In plain English, unhappy couples tend to blame each other instead of going with the flow.  How does this play out in perceived communications from mothers in law?

“Sense making is not only an intrapersonal process. In the case of the in-law triad, DILs are likely to turn to their spouses to make sense of their MILs’ hurtful message. In doing so, they get a sense for their spouses’ attributions, have the opportunity to compare them to their own, and may also engage in communicated sense making with their spouses.”

In other words, if the person’s spouse supports and confirms the experience that they are having, then the tendency is less likely to move toward internal attribution. Once again, in plain English, the in-law spouse will be more able to feel, “OK, that’s just my crazy mother in law.”  This ability hinges on the blood spouse taking seriously the pain inflicted and the boundary crossing or devaluing statements made by the mother in law.  If they are minimized, then the in-law spouse will feel as if he or she is alone and on the wrong side.

Care must be taken for the blood related spouse to not be the one to emphasize that “Mother doesn’t really mean it”, or “Ignore her, she is just eccentric.”  It is only when the blood related spouse validates the hurtful content that the in-law spouse can find the emotional space to consider the attributions as external instead of internal. In simple English, if you seek to minimize the pain of your spouse, he or she will feel ignored and it will maximize the pain.  But if you validate the pain, he or she can eventually come to understand how to minimize the pain.